diff --git a/Applications/ApplicationsLib/LinearSolverLibrarySetup.h b/Applications/ApplicationsLib/LinearSolverLibrarySetup.h
index 22049f47730b45b8afb5b29c12621b9c21c4f9df..dea388d10825d3c8d0d0eefd325533da790fbd97 100644
--- a/Applications/ApplicationsLib/LinearSolverLibrarySetup.h
+++ b/Applications/ApplicationsLib/LinearSolverLibrarySetup.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef APPLICATIONSLIB_LINEARSOLVERLIBRARYSETUP_H_
-#define APPLICATIONSLIB_LINEARSOLVERLIBRARYSETUP_H_
+#pragma once
 
 /// The LinearSolverLibrarySetup takes care of proper initialization and
 /// shutting down of an external linear solver library. The concrete
@@ -74,6 +73,3 @@ struct LinearSolverLibrarySetup final
 };
 }    // ApplicationsLib
 #endif
-
-
-#endif  // APPLICATIONSLIB_LINEARSOLVERLIBRARYSETUP_H_
diff --git a/Applications/ApplicationsLib/LogogSetup.h b/Applications/ApplicationsLib/LogogSetup.h
index e760b20770902559d6da6f9636f74cb6c49e64ef..9862f4a290b082622a7860ddc95d88073297a780 100644
--- a/Applications/ApplicationsLib/LogogSetup.h
+++ b/Applications/ApplicationsLib/LogogSetup.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef APPLICATIONSLIB_LOGOGSETUP_H_
-#define APPLICATIONSLIB_LOGOGSETUP_H_
+#pragma once
 
 #include <map>
 #include <memory>
@@ -83,5 +82,3 @@ private:
 };
 
 }    // ApplicationsLib
-
-#endif  // APPLICATIONSLIB_LOGOGSETUP_H_
diff --git a/Applications/ApplicationsLib/ProjectData.h b/Applications/ApplicationsLib/ProjectData.h
index 5cbe24c7ae54cc346908be3d25c504b6cf23b733..107de6b95120967d1f095778f3ee2cee261b7f59 100644
--- a/Applications/ApplicationsLib/ProjectData.h
+++ b/Applications/ApplicationsLib/ProjectData.h
@@ -10,8 +10,7 @@
  *
  */
 
-#ifndef PROJECTDATA_H_
-#define PROJECTDATA_H_
+#pragma once
 
 #include <boost/optional/optional.hpp>
 #include <map>
@@ -171,5 +170,3 @@ private:
              std::unique_ptr<MathLib::PiecewiseLinearInterpolation>>
         _curves;
 };
-
-#endif  // PROJECTDATA_H_
diff --git a/Applications/DataExplorer/Base/CheckboxDelegate.h b/Applications/DataExplorer/Base/CheckboxDelegate.h
index b8757197f9fdede4d5003d844e1dabaa2b348540..0e82581b7c8c870db8496d61918634edaf3cdbcc 100644
--- a/Applications/DataExplorer/Base/CheckboxDelegate.h
+++ b/Applications/DataExplorer/Base/CheckboxDelegate.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef CHECKBOXDELEGATE_H
-#define CHECKBOXDELEGATE_H
+#pragma once
 
 #include <QItemDelegate>
 
@@ -47,5 +46,3 @@ public:
 private:
     QRect checkboxRect(const QStyleOptionViewItem& viewItemStyleOptions) const;
 };
-
-#endif // CHECKBOXDELEGATE_H
diff --git a/Applications/DataExplorer/Base/ColorPickerPushButton.h b/Applications/DataExplorer/Base/ColorPickerPushButton.h
index e7706f6f4481eec9e049dbb8618fbe3f58500413..5596d767fc7e1888fc5aee51627799b4af9ed121 100644
--- a/Applications/DataExplorer/Base/ColorPickerPushButton.h
+++ b/Applications/DataExplorer/Base/ColorPickerPushButton.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef COLORPICKERPUSHBUTTON_H
-#define COLORPICKERPUSHBUTTON_H
+#pragma once
 
 // ** INCLUDES **
 #include <QPushButton>
@@ -51,5 +50,3 @@ signals:
     /// Is emitted when a color was picked from the dialog.
     void colorPicked(QColor);
 };
-
-#endif // COLORPICKERPUSHBUTTON_H
diff --git a/Applications/DataExplorer/Base/ImportFileTypes.h b/Applications/DataExplorer/Base/ImportFileTypes.h
index 489402ec4b357b402394d27b825806534e650d5c..86369b9a60bc36b57e42a4f8a6b278a540f945d4 100644
--- a/Applications/DataExplorer/Base/ImportFileTypes.h
+++ b/Applications/DataExplorer/Base/ImportFileTypes.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef IMPORTFILETYPES_H
-#define IMPORTFILETYPES_H
+#pragma once
 
 #include <string>
 
@@ -91,5 +90,3 @@ public:
 }
 
 };
-
-#endif //IMPORTFILETYPES_H
diff --git a/Applications/DataExplorer/Base/LastSavedFileDirectory.h b/Applications/DataExplorer/Base/LastSavedFileDirectory.h
index aa93c9d1562be43f8197cea3c248d6109867ba61..aa1027c887acfb262b3e276a935a3c5ab19657b9 100644
--- a/Applications/DataExplorer/Base/LastSavedFileDirectory.h
+++ b/Applications/DataExplorer/Base/LastSavedFileDirectory.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef LASTUSEDSAVEDFILEDIRECTORY_H
-#define LASTUSEDSAVEDFILEDIRECTORY_H
+#pragma once
 
 #include <QDir>
 #include <QFileInfo>
@@ -40,6 +39,3 @@ public:
     }
 
 };
-
-#endif //LASTUSEDSAVEDFILEDIRECTORY_H
-
diff --git a/Applications/DataExplorer/Base/OGSError.h b/Applications/DataExplorer/Base/OGSError.h
index 76749e0c438b42a6a7a69c5d8d54bbe7e16cbbd3..da722616c5d984fbe6fa8bcd1691cbb58d4a6e2a 100644
--- a/Applications/DataExplorer/Base/OGSError.h
+++ b/Applications/DataExplorer/Base/OGSError.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef OGSERROR_H
-#define OGSERROR_H
+#pragma once
 
 class QString;
 
@@ -53,5 +52,3 @@ protected:
     OGSError();
     ~OGSError();
 };
-
-#endif //OGSERROR_H
diff --git a/Applications/DataExplorer/Base/QNonScalableGraphicsTextItem.h b/Applications/DataExplorer/Base/QNonScalableGraphicsTextItem.h
index a84d1176cc1a2837b2cf34067547e6cad730a82f..ce9d3677f00f64f4aca6b5dad957ffc09ee62a94 100644
--- a/Applications/DataExplorer/Base/QNonScalableGraphicsTextItem.h
+++ b/Applications/DataExplorer/Base/QNonScalableGraphicsTextItem.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef QNONSCALABLETEXTITEM_H
-#define QNONSCALABLETEXTITEM_H
+#pragma once
 
 #include <QGraphicsTextItem>
 
@@ -32,5 +31,3 @@ public:
     void paint(QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget);
     virtual QRectF boundingRect() const;
 };
-
-#endif //QNONSCALABLETEXTITEM_H
diff --git a/Applications/DataExplorer/Base/QValueTooltipSlider.h b/Applications/DataExplorer/Base/QValueTooltipSlider.h
index c8653786f27b79222e3480a5a5870d77df949ef2..bdd247503c41a41897b4f8aa66372bb36b685f65 100644
--- a/Applications/DataExplorer/Base/QValueTooltipSlider.h
+++ b/Applications/DataExplorer/Base/QValueTooltipSlider.h
@@ -11,8 +11,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef QVALUETOOLTIPSLIDER_H
-#define QVALUETOOLTIPSLIDER_H
+#pragma once
 
 #include <QSlider>
 
@@ -31,5 +30,3 @@ public slots:
 
 protected:
 };
-
-#endif // QVALUETOOLTIPSLIDER_H
diff --git a/Applications/DataExplorer/Base/RecentFiles.h b/Applications/DataExplorer/Base/RecentFiles.h
index f71cf8f52dc50a737423d3ce6bdb4495c11e28c7..ec8d6b5456f490455e9fbfecfcc9cc54b816ac2e 100644
--- a/Applications/DataExplorer/Base/RecentFiles.h
+++ b/Applications/DataExplorer/Base/RecentFiles.h
@@ -11,8 +11,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef RECENTFILES_H
-#define RECENTFILES_H
+#pragma once
 
 // ** INCLUDES **
 #include <QAction>
@@ -72,5 +71,3 @@ private:
     enum { _maxFiles = 5 };
     QAction* _fileActions[_maxFiles];
 };
-
-#endif // RECENTFILES_H
diff --git a/Applications/DataExplorer/Base/StrictDoubleValidator.h b/Applications/DataExplorer/Base/StrictDoubleValidator.h
index 38e72c7b46b536d1c926c78d0c1298013b5f569d..bb3cd3b105052b0db7df80ef0d3c97db3edf6365 100644
--- a/Applications/DataExplorer/Base/StrictDoubleValidator.h
+++ b/Applications/DataExplorer/Base/StrictDoubleValidator.h
@@ -11,8 +11,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef STRICTDOUBLEVALIDATOR_H_
-#define STRICTDOUBLEVALIDATOR_H_
+#pragma once
 
 #include <QDoubleValidator>
 
@@ -40,5 +39,3 @@ public:
         return Acceptable;
     }
 };
-
-#endif /* STRICTDOUBLEVALIDATOR_H_ */
diff --git a/Applications/DataExplorer/Base/StrictIntValidator.h b/Applications/DataExplorer/Base/StrictIntValidator.h
index 433887627739d5a354bc4db1ccd6e7e2ddd2b8ca..bb1ba32ab526b57fc2629c58c8065b37d2255d44 100644
--- a/Applications/DataExplorer/Base/StrictIntValidator.h
+++ b/Applications/DataExplorer/Base/StrictIntValidator.h
@@ -12,8 +12,7 @@
 
  */
 
-#ifndef STRICTINTVALIDATOR_H_
-#define STRICTINTVALIDATOR_H_
+#pragma once
 
 #include <QIntValidator>
 
@@ -37,5 +36,3 @@ public:
         return Acceptable;
     }
 };
-
-#endif /* STRICTINTVALIDATOR_H_ */
diff --git a/Applications/DataExplorer/Base/TreeItem.h b/Applications/DataExplorer/Base/TreeItem.h
index dcc2b7378a65e300fbb633e38dcf467bcb9e969d..362c1789e19ae9d61a41d6f2bdd860ed1211e691 100644
--- a/Applications/DataExplorer/Base/TreeItem.h
+++ b/Applications/DataExplorer/Base/TreeItem.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef QTREEITEM_H
-#define QTREEITEM_H
+#pragma once
 
 #include <QList>
 #include <QVariant>
@@ -46,5 +45,3 @@ private:
     QList<QVariant> _itemData;
     TreeItem* _parentItem;
 };
-
-#endif //QTREEITEM_H
diff --git a/Applications/DataExplorer/Base/TreeModel.h b/Applications/DataExplorer/Base/TreeModel.h
index 4a8e4744266b26e82e6d7ea1961af2db5cc970ac..1323babbc78683af82df7df83c8c013d45373b48 100644
--- a/Applications/DataExplorer/Base/TreeModel.h
+++ b/Applications/DataExplorer/Base/TreeModel.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef QTREEMODEL_H
-#define QTREEMODEL_H
+#pragma once
 
 #include <QAbstractItemModel>
 
@@ -58,5 +57,3 @@ protected:
 private:
     void setupModelData(const QStringList &lines, TreeItem* parent);
 };
-
-#endif //QTREEMODEL_H
diff --git a/Applications/DataExplorer/Base/TreeModelIterator.h b/Applications/DataExplorer/Base/TreeModelIterator.h
index 0940dc6184fc9e5bbb1d37739b966137d318ea6d..7ed76018637051807535dc3e9423922494a5ff2a 100644
--- a/Applications/DataExplorer/Base/TreeModelIterator.h
+++ b/Applications/DataExplorer/Base/TreeModelIterator.h
@@ -12,8 +12,7 @@
 
  */
 
-#ifndef TREEMODELITERATOR_H
-#define TREEMODELITERATOR_H
+#pragma once
 
 // ** INCLUDES **
 #include <QStack>
@@ -61,5 +60,3 @@ private:
     /// \brief The traversal implementation.
     TreeItem* next(const TreeItem* current);
 };
-
-#endif // TREEMODELITERATOR_H
diff --git a/Applications/DataExplorer/Base/modeltest.h b/Applications/DataExplorer/Base/modeltest.h
index c6f090e60e1465962abd46e0b5019a85fd597277..d2954429c0ca99649f72bc2ed2969b3b6f512638 100644
--- a/Applications/DataExplorer/Base/modeltest.h
+++ b/Applications/DataExplorer/Base/modeltest.h
@@ -21,8 +21,7 @@
 **
 ****************************************************************************/
 
-#ifndef MODELTEST_H
-#define MODELTEST_H
+#pragma once
 
 #include <QtCore/QAbstractItemModel>
 #include <QtCore/QObject>
@@ -72,5 +71,3 @@ private:
 
     QList<QPersistentModelIndex> changing;
 };
-
-#endif
diff --git a/Applications/DataExplorer/DataView/AddLayerToMeshDialog.h b/Applications/DataExplorer/DataView/AddLayerToMeshDialog.h
index af9f4dfdfbc3f22dc9dc1b9f4482637bbd1d37bc..1563895a2112e24dfd816c3789bae705b0dc9b28 100644
--- a/Applications/DataExplorer/DataView/AddLayerToMeshDialog.h
+++ b/Applications/DataExplorer/DataView/AddLayerToMeshDialog.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef ADDLAYERTOMESHDIALOG_H
-#define ADDLAYERTOMESHDIALOG_H
+#pragma once
 
 #include "ui_AddLayerToMesh.h"
 
@@ -46,5 +45,3 @@ private slots:
     /// Instructions if the Cancel-Button has been pressed.
     void reject();
 };
-
-#endif //ADDLAYERTOMESHDIALOG_H
diff --git a/Applications/DataExplorer/DataView/BaseItem.h b/Applications/DataExplorer/DataView/BaseItem.h
index 444f5c245116b63994a268859f8070e342d2af54..b5f897282b8d7fbe045cb63a34655f1e4bb6f041 100644
--- a/Applications/DataExplorer/DataView/BaseItem.h
+++ b/Applications/DataExplorer/DataView/BaseItem.h
@@ -11,8 +11,7 @@
  *              http://www.opengeosys.org/project/license
  *
  */
-#ifndef BASEITEM_H
-#define BASEITEM_H
+#pragma once
 
 #include "Point.h"
 
@@ -61,5 +60,3 @@ private:
     /// visualization pipeline.
     vtkPolyDataAlgorithm* _vtkSource;
 };
-
-#endif //BASEITEM_H
diff --git a/Applications/DataExplorer/DataView/ColorTableModel.h b/Applications/DataExplorer/DataView/ColorTableModel.h
index 1b6da36ece146d05cb7b176025c89afd227f5057..97a94ac11d076924e1e0c9fb6aa9fbcc403c206b 100644
--- a/Applications/DataExplorer/DataView/ColorTableModel.h
+++ b/Applications/DataExplorer/DataView/ColorTableModel.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef COLORTABLEMODEL_H
-#define COLORTABLEMODEL_H
+#pragma once
 
 #include <QAbstractTableModel>
 #include <QColor>
@@ -50,4 +49,3 @@ private:
 
     QList< QPair<QString, QColor> > _listOfPairs;
 };
-#endif // COLORTABLEMODEL_H
diff --git a/Applications/DataExplorer/DataView/ColorTableView.h b/Applications/DataExplorer/DataView/ColorTableView.h
index 80aa1629f4c9502dc3b4604722811ffe91186ebd..3892db6945cc61cd8ae52c8185a7d521a2457a24 100644
--- a/Applications/DataExplorer/DataView/ColorTableView.h
+++ b/Applications/DataExplorer/DataView/ColorTableView.h
@@ -11,8 +11,7 @@
  *              http://www.opengeosys.org/project/license
  *
  */
-#ifndef COLORTABLEVIEW_H
-#define COLORTABLEVIEW_H
+#pragma once
 
 #include <QItemDelegate>
 #include <QTableView>
@@ -46,6 +45,3 @@ public:
 
     QSize sizeHint( const QStyleOptionViewItem &option, const QModelIndex &index ) const;
 };
-
-#endif // COLORTABLEVIEW_H
-
diff --git a/Applications/DataExplorer/DataView/CondFromRasterDialog.h b/Applications/DataExplorer/DataView/CondFromRasterDialog.h
index d843785c81dab5ace1df9367b86405b9b9dc21fd..4be6b081793635256a7ccf178e0669abf9d6ae0f 100644
--- a/Applications/DataExplorer/DataView/CondFromRasterDialog.h
+++ b/Applications/DataExplorer/DataView/CondFromRasterDialog.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef CONDFROMRASTERDIALOG_H
-#define CONDFROMRASTERDIALOG_H
+#pragma once
 
 #include "ui_CondFromRaster.h"
 #include <QDialog>
@@ -53,5 +52,3 @@ signals:
     void directNodesWritten(std::string);
     void transmitDisValues(std::vector< std::pair<std::size_t,double> >);
 };
-
-#endif //CONDFROMRASTERDIALOG_H
diff --git a/Applications/DataExplorer/DataView/CondItem.h b/Applications/DataExplorer/DataView/CondItem.h
index 931b4c68797fe7693e04077c5c97b0a21b97e752..b4ac423753b58b543cf9a51f1e059eca1a9e5daa 100644
--- a/Applications/DataExplorer/DataView/CondItem.h
+++ b/Applications/DataExplorer/DataView/CondItem.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef CONDITEM_H
-#define CONDITEM_H
+#pragma once
 
 #include "FEMCondition.h"
 #include "TreeItem.h"
@@ -43,5 +42,3 @@ public:
 private:
     const FEMCondition* _item;
 };
-
-#endif //CONDITEM_H
diff --git a/Applications/DataExplorer/DataView/CondObjectListItem.h b/Applications/DataExplorer/DataView/CondObjectListItem.h
index 420d166c620d9c90ea9cebbf1141815cac04eb53..272a7ee9d8ab68e7fb3926d91a79de2dc73ce912 100644
--- a/Applications/DataExplorer/DataView/CondObjectListItem.h
+++ b/Applications/DataExplorer/DataView/CondObjectListItem.h
@@ -12,8 +12,7 @@
  *
  *
  */
-#ifndef CONDOBJECTLISTITEM_H
-#define CONDOBJECTLISTITEM_H
+#pragma once
 
 #include "FEMCondition.h"
 #include "TreeItem.h"
@@ -74,5 +73,3 @@ private:
     FEMCondition::CondType _type;
     std::vector<FEMCondition*>* _cond_vec;
 };
-
-#endif //CONDOBJECTLISTITEM_H
diff --git a/Applications/DataExplorer/DataView/CreateStructuredGridDialog.h b/Applications/DataExplorer/DataView/CreateStructuredGridDialog.h
index a49ea00d89271ad0a4121dbbdfc198b7fbd6d733..29b9ae6cfd82635dcd1376a5d37ad20c800db55b 100644
--- a/Applications/DataExplorer/DataView/CreateStructuredGridDialog.h
+++ b/Applications/DataExplorer/DataView/CreateStructuredGridDialog.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef CREATESTRUCTUREDGRIDDIALOG_H
-#define CREATESTRUCTUREDGRIDDIALOG_H
+#pragma once
 
 #include "ui_CreateStructuredGrid.h"
 #include <QDialog>
@@ -56,5 +55,3 @@ private:
 signals:
     void meshAdded(MeshLib::Mesh* mesh);
 };
-
-#endif // CREATESTRUCTUREDGRIDDIALOG_H
diff --git a/Applications/DataExplorer/DataView/DataExplorerSettingsDialog.h b/Applications/DataExplorer/DataView/DataExplorerSettingsDialog.h
index a9ba1e170b8339369f8c93c47ddb6110eb28aa86..ed40b7a5dc904f1d65693ec9239a6ee86294a327 100644
--- a/Applications/DataExplorer/DataView/DataExplorerSettingsDialog.h
+++ b/Applications/DataExplorer/DataView/DataExplorerSettingsDialog.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef DATAEXPLORERSETTINGSDIALOG_H
-#define DATAEXPLORERSETTINGSDIALOG_H
+#pragma once
 
 #include "ui_DataExplorerSettings.h"
 #include <QDialog>
@@ -40,5 +39,3 @@ private slots:
     void reject() { this->done(QDialog::Rejected); };
 
 };
-
-#endif //DATAEXPLORERSETTINGSDIALOG_H
diff --git a/Applications/DataExplorer/DataView/DiagramView/DetailWindow.h b/Applications/DataExplorer/DataView/DiagramView/DetailWindow.h
index 82d8e7957f87f20cd1e47c65726852e0311bf5ba..48f1c55414b83b22b71de4b90f31a853677bd4e6 100644
--- a/Applications/DataExplorer/DataView/DiagramView/DetailWindow.h
+++ b/Applications/DataExplorer/DataView/DiagramView/DetailWindow.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef DETAILWINDOW_H
-#define DETAILWINDOW_H
+#pragma once
 
 #include "ui_DetailWindow.h"
 #include <QWidget>
@@ -65,5 +64,3 @@ private slots:
     void on_addDataButton_clicked();
     void on_closeButton_clicked();
 };
-
-#endif //DETAILWINDOW_H
diff --git a/Applications/DataExplorer/DataView/DiagramView/DiagramList.h b/Applications/DataExplorer/DataView/DiagramView/DiagramList.h
index f5d836502fe3495b8e6e84e0c01e7169b1075b88..1471bb6e66e57a4238114fce9882aba32f85fee6 100644
--- a/Applications/DataExplorer/DataView/DiagramView/DiagramList.h
+++ b/Applications/DataExplorer/DataView/DiagramView/DiagramList.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef DIAGRAMLIST_H
-#define DIAGRAMLIST_H
+#pragma once
 
 #include <QColor>
 #include <QDateTime>
@@ -184,5 +183,3 @@ private:
     QColor _colour;
     QDateTime _startDate;
 };
-
-#endif //DIAGRAMLIST_H
diff --git a/Applications/DataExplorer/DataView/DiagramView/DiagramPrefsDialog.h b/Applications/DataExplorer/DataView/DiagramView/DiagramPrefsDialog.h
index 2e10920bfe94a288fc3fe732792bbc14127960fe..696e81b577c9d45437cdc670925bff507b75afbc 100644
--- a/Applications/DataExplorer/DataView/DiagramView/DiagramPrefsDialog.h
+++ b/Applications/DataExplorer/DataView/DiagramView/DiagramPrefsDialog.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef DIAGRAMPREFSDIALOG_H
-#define DIAGRAMPREFSDIALOG_H
+#pragma once
 
 #include "ui_DiagramPrefs.h"
 #include <QMainWindow>
@@ -115,5 +114,3 @@ private slots:
 
 signals:
 };
-
-#endif //DIAGRAMPREFSDIALOG_H
diff --git a/Applications/DataExplorer/DataView/DiagramView/DiagramScene.h b/Applications/DataExplorer/DataView/DiagramView/DiagramScene.h
index 7c7e8b3f6e7ec47d306e8bcd14a6ae747bd187a3..511ed66e63fb6dc10930eac953e96f743730b98c 100644
--- a/Applications/DataExplorer/DataView/DiagramView/DiagramScene.h
+++ b/Applications/DataExplorer/DataView/DiagramView/DiagramScene.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef DIAGRAMSCENE_H
-#define DIAGRAMSCENE_H
+#pragma once
 
 #include "DiagramList.h"
 #include "QArrow.h"
@@ -79,5 +78,3 @@ private:
     QVector<QNonScalableGraphicsTextItem*> _xTicksText;
     QVector<QNonScalableGraphicsTextItem*> _yTicksText;
 };
-
-#endif //DIAGRAMSCENE_H
diff --git a/Applications/DataExplorer/DataView/DiagramView/DiagramView.h b/Applications/DataExplorer/DataView/DiagramView/DiagramView.h
index a9730818304dc8f5e39bcf7442cf6511340c170b..927eaa98daac3b3d9e497ff43a7fb8cfc94ae197 100644
--- a/Applications/DataExplorer/DataView/DiagramView/DiagramView.h
+++ b/Applications/DataExplorer/DataView/DiagramView/DiagramView.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef DIAGRAMVIEW_H
-#define DIAGRAMVIEW_H
+#pragma once
 
 #include "DiagramScene.h"
 #include <QGraphicsView>
@@ -61,5 +60,3 @@ private:
 
     DiagramScene* _scene;
 };
-
-#endif //DIAGRAMVIEW_H
diff --git a/Applications/DataExplorer/DataView/DiagramView/QArrow.h b/Applications/DataExplorer/DataView/DiagramView/QArrow.h
index 433cf351eb6055df96d9546ad8c40eb923f1b7d2..8df5ac7f365cf5ec171fde7a7f113e769029658c 100644
--- a/Applications/DataExplorer/DataView/DiagramView/QArrow.h
+++ b/Applications/DataExplorer/DataView/DiagramView/QArrow.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef QARROW_H
-#define QARROW_H
+#pragma once
 
 #include <QGraphicsItem>
 #include <QPen>
@@ -47,5 +46,3 @@ private:
     float _headWidth;
     QPen _arrowPen;
 };
-
-#endif //QARROW_H
diff --git a/Applications/DataExplorer/DataView/DiagramView/QGraphicsGrid.h b/Applications/DataExplorer/DataView/DiagramView/QGraphicsGrid.h
index 80c814686dbfb99361915842595de4eb4f0d4abc..ba529f9c648f233e79991876f2ff08be46f74022 100644
--- a/Applications/DataExplorer/DataView/DiagramView/QGraphicsGrid.h
+++ b/Applications/DataExplorer/DataView/DiagramView/QGraphicsGrid.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef QGRAPHICSGRID_H
-#define QGRAPHICSGRID_H
+#pragma once
 
 #include <QGraphicsItem>
 #include <QPen>
@@ -68,5 +67,3 @@ private:
     int _numberOfYCells;
     bool _showTicks;
 };
-
-#endif //QGRAPHICSGRID_H
diff --git a/Applications/DataExplorer/DataView/DirectConditionGenerator.h b/Applications/DataExplorer/DataView/DirectConditionGenerator.h
index c4680257eaf1d90402fbe5399582f875c9f83e5c..0985f0875a1d10f32a2bcb1ed5722fcc28ec4f54 100644
--- a/Applications/DataExplorer/DataView/DirectConditionGenerator.h
+++ b/Applications/DataExplorer/DataView/DirectConditionGenerator.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef DIRECTCONDITIONGENERATOR_H
-#define DIRECTCONDITIONGENERATOR_H
+#pragma once
 
 #include <vector>
 #include <string>
@@ -38,6 +37,3 @@ private:
     std::vector< std::pair<std::size_t,double> > _direct_values;
 
 };
-
-#endif // DIRECTCONDITIONGENERATOR_H
-
diff --git a/Applications/DataExplorer/DataView/ElementTreeModel.h b/Applications/DataExplorer/DataView/ElementTreeModel.h
index 054ea455f56ce93cefb54f713019e308947187a8..eb860ac957387254c213e874fd7ce1084c95e3f5 100644
--- a/Applications/DataExplorer/DataView/ElementTreeModel.h
+++ b/Applications/DataExplorer/DataView/ElementTreeModel.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef ELEMENTTREEMODEL_H
-#define ELEMENTTREEMODEL_H
+#pragma once
 
 #include <array>
 #include "TreeModel.h"
@@ -52,5 +51,3 @@ private:
     vtkUnstructuredGridAlgorithm const* _mesh_source;
 
 };
-
-#endif //ELEMENTTREEMODEL_H
diff --git a/Applications/DataExplorer/DataView/ElementTreeView.h b/Applications/DataExplorer/DataView/ElementTreeView.h
index c093eed267ed6115c2883b7254e769cc66c7c6ed..a3531ba226d4fa0404801ed1985ea7f69525c3e1 100644
--- a/Applications/DataExplorer/DataView/ElementTreeView.h
+++ b/Applications/DataExplorer/DataView/ElementTreeView.h
@@ -11,8 +11,7 @@
  *              http://www.opengeosys.org/project/license
  *
  */
-#ifndef ELEMENTTREEVIEW_H
-#define ELEMENTTREEVIEW_H
+#pragma once
 
 #include <QTreeView>
 
@@ -40,7 +39,3 @@ signals:
     void nodeSelected(vtkUnstructuredGridAlgorithm const*const, unsigned, bool);
     void removeSelectedMeshComponent();
 };
-
-
-#endif // ELEMENTTREEVIEW_H
-
diff --git a/Applications/DataExplorer/DataView/GEOModels.h b/Applications/DataExplorer/DataView/GEOModels.h
index 4e33203348c1457ee332d3d7502c1a4aed231205..eebcf35cba6ca8419c6c7365cd3fdc74ef59032c 100644
--- a/Applications/DataExplorer/DataView/GEOModels.h
+++ b/Applications/DataExplorer/DataView/GEOModels.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef GEOMODELS_H
-#define GEOMODELS_H
+#pragma once
 
 #include <QObject>
 
@@ -170,6 +169,3 @@ public:
 private:
     GEOModels& _geo_models;
 };
-
-
-#endif // GEOMODELS_H
diff --git a/Applications/DataExplorer/DataView/GMSHPrefsDialog.h b/Applications/DataExplorer/DataView/GMSHPrefsDialog.h
index c1b80d1717cdf68479c33451e801d01ff94de7a1..768b7d688624a01384189dd14da33d5e85d483de 100644
--- a/Applications/DataExplorer/DataView/GMSHPrefsDialog.h
+++ b/Applications/DataExplorer/DataView/GMSHPrefsDialog.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef GMSHPREFSDIALOG_H
-#define GMSHPREFSDIALOG_H
+#pragma once
 
 #include "ui_GMSHPrefs.h"
 #include <QDialog>
@@ -56,5 +55,3 @@ private slots:
 signals:
     void requestMeshing(std::vector<std::string> &, unsigned, double, double, double, bool);
 };
-
-#endif //GMSHPREFSDIALOG_H
diff --git a/Applications/DataExplorer/DataView/GeoObjectListItem.h b/Applications/DataExplorer/DataView/GeoObjectListItem.h
index 5bf78816912f6b5c1615b48f550476d1794d317e..a85c9b86b89f399f24b047f81b2b8d78a0e6d48f 100644
--- a/Applications/DataExplorer/DataView/GeoObjectListItem.h
+++ b/Applications/DataExplorer/DataView/GeoObjectListItem.h
@@ -12,8 +12,7 @@
  *
  *
  */
-#ifndef GEOOBJECTLISTITEM_H
-#define GEOOBJECTLISTITEM_H
+#pragma once
 
 #include "TreeItem.h"
 
@@ -88,5 +87,3 @@ private:
 
     GeoLib::GEOTYPE _type;
 };
-
-#endif //GEOOBJECTLISTITEM_H
diff --git a/Applications/DataExplorer/DataView/GeoOnMeshMappingDialog.h b/Applications/DataExplorer/DataView/GeoOnMeshMappingDialog.h
index aab8ff192364c9ced629ba96a63c9ed3ec7f3ff2..985c6cde38868580322fc7f0bf103af6bf31d8b1 100644
--- a/Applications/DataExplorer/DataView/GeoOnMeshMappingDialog.h
+++ b/Applications/DataExplorer/DataView/GeoOnMeshMappingDialog.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef GEOTOMESHMAPPINGDIALOG_H
-#define GEOTOMESHMAPPINGDIALOG_H
+#pragma once
 
 #include "ui_GeoOnMeshMapping.h"
 #include <QDialog>
@@ -55,5 +54,3 @@ private slots:
     void reject() { this->done(QDialog::Rejected); };
 
 };
-
-#endif //GEOTOMESHMAPPINGDIALOG_H
diff --git a/Applications/DataExplorer/DataView/GeoTabWidget.h b/Applications/DataExplorer/DataView/GeoTabWidget.h
index aa6f5ebd65d9e2f0768184b93dffe8479dfb1587..825a3916c6845eb105d3cc0f03ffe698217e7f37 100644
--- a/Applications/DataExplorer/DataView/GeoTabWidget.h
+++ b/Applications/DataExplorer/DataView/GeoTabWidget.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef GEOTABWIDGET_H
-#define GEOTABWIDGET_H
+#pragma once
 
 // ** INCLUDES **
 #include "ui_GeoTabWidgetBase.h"
@@ -35,5 +34,3 @@ private slots:
     void enableRemoveButton(bool enable) { this->removeGeoPushButton->setEnabled(enable); };
 
 };
-
-#endif // GEOTABWIDGET_H
diff --git a/Applications/DataExplorer/DataView/GeoTreeItem.h b/Applications/DataExplorer/DataView/GeoTreeItem.h
index b113288c4ea05635632a1e11ddd5a70a9f1c5cd6..45d3c41a2c9d4153e10aa656b7c9d13eaf1ec565 100644
--- a/Applications/DataExplorer/DataView/GeoTreeItem.h
+++ b/Applications/DataExplorer/DataView/GeoTreeItem.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef GEOTREEITEM_H
-#define GEOTREEITEM_H
+#pragma once
 
 #include "TreeItem.h"
 
@@ -44,5 +43,3 @@ public:
 private:
     const GeoLib::GeoObject* _item;
 };
-
-#endif //GEOTREEITEM_H
diff --git a/Applications/DataExplorer/DataView/GeoTreeModel.h b/Applications/DataExplorer/DataView/GeoTreeModel.h
index 6d380a006740402db6bb4dc52ad8bece1a779355..543a77ef9cf1683a84b1e41e4834a28fe1080486 100644
--- a/Applications/DataExplorer/DataView/GeoTreeModel.h
+++ b/Applications/DataExplorer/DataView/GeoTreeModel.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef GEOTREEMODEL_H
-#define GEOTREEMODEL_H
+#pragma once
 
 #include <vector>
 
@@ -96,5 +95,3 @@ private:
 
     std::vector<GeoTreeItem*> _lists;
 };
-
-#endif //GEOTREEMODEL_H
diff --git a/Applications/DataExplorer/DataView/GeoTreeView.h b/Applications/DataExplorer/DataView/GeoTreeView.h
index 251fa34c84039e9db5ce6fbb267dddaf380d859c..dd4f27cb9dfbb300557fd5d68029e315c665c9bb 100644
--- a/Applications/DataExplorer/DataView/GeoTreeView.h
+++ b/Applications/DataExplorer/DataView/GeoTreeView.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef GEOTREEVIEW_H
-#define GEOTREEVIEW_H
+#pragma once
 
 #include "GeoType.h"
 
@@ -86,5 +85,3 @@ signals:
     void requestNameChangeDialog(const std::string&, const GeoLib::GEOTYPE, const std::size_t);
     //void saveFEMConditionsRequested(QString, QString);
 };
-
-#endif //GEOTREEVIEW_H
diff --git a/Applications/DataExplorer/DataView/LicenseDialog.h b/Applications/DataExplorer/DataView/LicenseDialog.h
index db142c41a052c262a9b0d70e582f4dfbbe8128fa..0e9b60923e7f49b5378df97b6bb5591f0f011e01 100644
--- a/Applications/DataExplorer/DataView/LicenseDialog.h
+++ b/Applications/DataExplorer/DataView/LicenseDialog.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef LICENSEDIALOG_H
-#define LICENSEDIALOG_H
+#pragma once
 
 #include "ui_License.h"
 #include <QDialog>
@@ -36,5 +35,3 @@ private slots:
     void on_okPushButton_pressed();
 
 };
-
-#endif //LICENSEDIALOG_H
diff --git a/Applications/DataExplorer/DataView/LineEditDialog.h b/Applications/DataExplorer/DataView/LineEditDialog.h
index 7cb34e28d63fd9ba6b73035cd8ae2f825878c43c..8db79316cf0ccc13511ddce08aaf43ec75dfda7a 100644
--- a/Applications/DataExplorer/DataView/LineEditDialog.h
+++ b/Applications/DataExplorer/DataView/LineEditDialog.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef LINEEDITDIALOG_H
-#define LINEEDITDIALOG_H
+#pragma once
 
 #include "ui_LineEdit.h"
 #include <QDialog>
@@ -64,5 +63,3 @@ signals:
                           bool);
     void triangulateSurface(const GeoLib::Polyline);
 };
-
-#endif //LINEEDITDIALOG_H
diff --git a/Applications/DataExplorer/DataView/LinearEditDialog.h b/Applications/DataExplorer/DataView/LinearEditDialog.h
index fed2d7e71b7797170a93996e817376527ed361f4..d35d57bb0a186d04a940511b6c30410d081234b3 100644
--- a/Applications/DataExplorer/DataView/LinearEditDialog.h
+++ b/Applications/DataExplorer/DataView/LinearEditDialog.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef LINEAREDITDIALOG_H
-#define LINEAREDITDIALOG_H
+#pragma once
 
 #include "ui_LinearEdit.h"
 #include <QDialog>
@@ -48,5 +47,3 @@ private slots:
 signals:
     void transmitDisValues(std::vector< std::pair<std::size_t,double> >);
 };
-
-#endif //LINEAREDITDIALOG_H
diff --git a/Applications/DataExplorer/DataView/MergeGeometriesDialog.h b/Applications/DataExplorer/DataView/MergeGeometriesDialog.h
index d9d51feb3560135ee7202ab6c36527b377d87b8d..ad9c1bac5f555bf455d4212f1fca51b35a9b19c4 100644
--- a/Applications/DataExplorer/DataView/MergeGeometriesDialog.h
+++ b/Applications/DataExplorer/DataView/MergeGeometriesDialog.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef MERGEGEOMETRIESDIALOG_H
-#define MERGEGEOMETRIESDIALOG_H
+#pragma once
 
 #include "ui_MergeGeometries.h"
 #include <QDialog>
@@ -57,5 +56,3 @@ private slots:
     /// Instructions if the Cancel-Button has been pressed.
     void reject();
 };
-
-#endif //MERGEGEOMETRIESDIALOG_H
diff --git a/Applications/DataExplorer/DataView/MeshAnalysisDialog.h b/Applications/DataExplorer/DataView/MeshAnalysisDialog.h
index a53aa896e7aac95728f872bc9ead3cb3b2db35e2..7fde240dc4323065714905fb20c670dd0b49fff3 100644
--- a/Applications/DataExplorer/DataView/MeshAnalysisDialog.h
+++ b/Applications/DataExplorer/DataView/MeshAnalysisDialog.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef MESHANALYSISDIALOG_H
-#define MESHANALYSISDIALOG_H
+#pragma once
 
 #include <memory>
 
@@ -55,5 +54,3 @@ private slots:
     /// Closes the dialog
     void on_closeButton_pressed() { this->close(); }
 };
-
-#endif //MESHANALYSISDIALOG_H
diff --git a/Applications/DataExplorer/DataView/MeshElementRemovalDialog.h b/Applications/DataExplorer/DataView/MeshElementRemovalDialog.h
index 3a1078f2d2a468d3e9d8a15e03e5dfa8cee5ffbe..1c0778f3a04a285014cb50f69f9ecc48c9008ce3 100644
--- a/Applications/DataExplorer/DataView/MeshElementRemovalDialog.h
+++ b/Applications/DataExplorer/DataView/MeshElementRemovalDialog.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef MESHELEMENTREMOVALDIALOG_H
-#define MESHELEMENTREMOVALDIALOG_H
+#pragma once
 
 #include "ui_MeshElementRemoval.h"
 #include <QDialog>
@@ -57,5 +56,3 @@ private:
 signals:
     void meshAdded(MeshLib::Mesh* mesh);
 };
-
-#endif //MESHELEMENTREMOVALDIALOG_H
diff --git a/Applications/DataExplorer/DataView/MeshLayerEditDialog.h b/Applications/DataExplorer/DataView/MeshLayerEditDialog.h
index ff07914c41d3f8c9509e32b0c2d65a210fbc1498..bca05f792bf9ad7b6ff958745edff1b679a575a1 100644
--- a/Applications/DataExplorer/DataView/MeshLayerEditDialog.h
+++ b/Applications/DataExplorer/DataView/MeshLayerEditDialog.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef MESHLAYEREDITDIALOG_H
-#define MESHLAYEREDITDIALOG_H
+#pragma once
 
 #include "ui_MeshLayerEdit.h"
 #include <QDialog>
@@ -81,5 +80,3 @@ private slots:
 signals:
     void mshEditFinished(MeshLib::Mesh*);
 };
-
-#endif //MESHLAYEREDITDIALOG_H
diff --git a/Applications/DataExplorer/DataView/MeshMapping2DDialog.h b/Applications/DataExplorer/DataView/MeshMapping2DDialog.h
index f563c2d8e131ed612314c904d2dc6544b6c8747c..7702cd357b47c1eb4f72758c6d2180d65b19a79c 100644
--- a/Applications/DataExplorer/DataView/MeshMapping2DDialog.h
+++ b/Applications/DataExplorer/DataView/MeshMapping2DDialog.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MESHMAPPING2DDIALOG_H
-#define MESHMAPPING2DDIALOG_H
+#pragma once
 
 #include "ui_MeshMapping2D.h"
 
@@ -43,5 +42,3 @@ private slots:
     /// Instructions if the Cancel-Button has been pressed.
     void reject() { this->done(QDialog::Rejected); }
 };
-
-#endif //MESHMAPPING2DDIALOG_H
diff --git a/Applications/DataExplorer/DataView/MeshQualitySelectionDialog.h b/Applications/DataExplorer/DataView/MeshQualitySelectionDialog.h
index d92eadb00cbbc028a4b90fa0683e5153459c8213..725028376249e9f70f0f11850e2568afc84240b3 100644
--- a/Applications/DataExplorer/DataView/MeshQualitySelectionDialog.h
+++ b/Applications/DataExplorer/DataView/MeshQualitySelectionDialog.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef MESHQUALITYSELECTIONDIALOG_H
-#define MESHQUALITYSELECTIONDIALOG_H
+#pragma once
 
 #include "MeshEnums.h"
 #include "ui_MeshQualitySelection.h"
@@ -52,5 +51,3 @@ private slots:
     void accept();
     void reject();
 };
-
-#endif //MESHQUALITYSELECTIONDIALOG_H
diff --git a/Applications/DataExplorer/DataView/MeshValueEditDialog.h b/Applications/DataExplorer/DataView/MeshValueEditDialog.h
index 75bf93f52bb87a6dc90c93411ade2d9a933f9cde..df4de5b0a15868cde7af5a199e3a64f1f0d715f8 100644
--- a/Applications/DataExplorer/DataView/MeshValueEditDialog.h
+++ b/Applications/DataExplorer/DataView/MeshValueEditDialog.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef MESHVALUEEDITDIALOG_H
-#define MESHVALUEEDITDIALOG_H
+#pragma once
 
 #include "ui_MeshValueEdit.h"
 
@@ -51,5 +50,3 @@ private slots:
 signals:
     void valueEditFinished(MeshLib::Mesh*);
 };
-
-#endif //MESHVALUEEDITDIALOG_H
diff --git a/Applications/DataExplorer/DataView/ModelTreeItem.h b/Applications/DataExplorer/DataView/ModelTreeItem.h
index 0df9866a298fe68b3c44fdc64d1e908867907260..58a86176b424cd37fe22ff929d5a510f72422785 100644
--- a/Applications/DataExplorer/DataView/ModelTreeItem.h
+++ b/Applications/DataExplorer/DataView/ModelTreeItem.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef QMODELTREEITEM_H
-#define QMODELTREEITEM_H
+#pragma once
 
 #include "BaseItem.h"
 #include "Station.h"
@@ -52,5 +51,3 @@ private:
     BaseItem* _item;
     GeoLib::Station* _stn;
 };
-
-#endif //QMODELTREEITEM_H
diff --git a/Applications/DataExplorer/DataView/ModellingTabWidget.h b/Applications/DataExplorer/DataView/ModellingTabWidget.h
index 7001914e4b771e7c074d567ceea23cc4ef7a76aa..87bcb53b3881b5667a153f2874ea6f2f114b3b42 100644
--- a/Applications/DataExplorer/DataView/ModellingTabWidget.h
+++ b/Applications/DataExplorer/DataView/ModellingTabWidget.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef MODELLINGTABWIDGET_H
-#define MODELLINGTABWIDGET_H
+#pragma once
 
 // ** INCLUDES **
 #include "ui_ModellingTabWidgetBase.h"
@@ -32,5 +31,3 @@ private slots:
 
 signals:
 };
-
-#endif // MODELLINGTABWIDGET_H
diff --git a/Applications/DataExplorer/DataView/MshEditDialog.h b/Applications/DataExplorer/DataView/MshEditDialog.h
index 4c8a476d5383e7089bae6ec8a114ce4780a7d1dd..48144a717eb04d11f8268bdeba75cdd15be6cb65 100644
--- a/Applications/DataExplorer/DataView/MshEditDialog.h
+++ b/Applications/DataExplorer/DataView/MshEditDialog.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef MSHEDITDIALOG_H
-#define MSHEDITDIALOG_H
+#pragma once
 
 #include "ui_MshEdit.h"
 #include <QDialog>
@@ -82,5 +81,3 @@ private slots:
 signals:
     void mshEditFinished(MeshLib::Mesh*);
 };
-
-#endif //MSHEDITDIALOG_H
diff --git a/Applications/DataExplorer/DataView/MshItem.h b/Applications/DataExplorer/DataView/MshItem.h
index 71a11dc676eb98d67efc36d57f909efcf667abd1..be5eb456ecad908074c7414634e0545c2e36589a 100644
--- a/Applications/DataExplorer/DataView/MshItem.h
+++ b/Applications/DataExplorer/DataView/MshItem.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef MSHITEM_H
-#define MSHITEM_H
+#pragma once
 
 #include "TreeItem.h"
 
@@ -47,5 +46,3 @@ public:
 private:
     MeshLib::VtkMappedMeshSource * _mesh_source;
 };
-
-#endif //MSHITEM_H
diff --git a/Applications/DataExplorer/DataView/MshModel.h b/Applications/DataExplorer/DataView/MshModel.h
index adcde8ff6cfb085796b59ec7b11c8bc25df5e7ee..a0f4d9bef343c3a294c0b655cec81bd440f7ad8d 100644
--- a/Applications/DataExplorer/DataView/MshModel.h
+++ b/Applications/DataExplorer/DataView/MshModel.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef MSHMODEL_H
-#define MSHMODEL_H
+#pragma once
 
 // ** INCLUDES **
 #ifndef Q_MOC_RUN  // See: https://bugreports.qt-project.org/browse/QTBUG-22829
@@ -84,5 +83,3 @@ signals:
     void meshAdded(MshModel*, const QModelIndex&);
     void meshRemoved(MshModel*, const QModelIndex&);
 };
-
-#endif // MSHMODEL_H
diff --git a/Applications/DataExplorer/DataView/MshTabWidget.h b/Applications/DataExplorer/DataView/MshTabWidget.h
index 69a8c2632189b915f083cca8b0b91224239f426e..ec7b8196214707873a8cee714f9f3937e6fab325 100644
--- a/Applications/DataExplorer/DataView/MshTabWidget.h
+++ b/Applications/DataExplorer/DataView/MshTabWidget.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef MSHTABWIDGET_H
-#define MSHTABWIDGET_H
+#pragma once
 
 // ** INCLUDES **
 #include "ui_MshTabWidgetBase.h"
@@ -32,5 +31,3 @@ private slots:
     void enableSaveButton(bool enable) { this->saveMeshPushButton->setEnabled(enable); };
     void enableRemoveButton(bool enable) { this->removeMeshPushButton->setEnabled(enable); };
 };
-
-#endif // MSHTABWIDGET_H
diff --git a/Applications/DataExplorer/DataView/MshView.h b/Applications/DataExplorer/DataView/MshView.h
index a187a6c6a8791d95f59e960883efcebd00404603..4eb055ebcd18dee33982fe8e1e2ed98e96d4e4da 100644
--- a/Applications/DataExplorer/DataView/MshView.h
+++ b/Applications/DataExplorer/DataView/MshView.h
@@ -11,8 +11,7 @@
  *              http://www.opengeosys.org/project/license
  *
  */
-#ifndef MSHVIEW_H
-#define MSHVIEW_H
+#pragma once
 
 #include "Point.h"
 #include "GeoType.h"
@@ -110,4 +109,3 @@ signals:
     void saveMeshAction();
 
 };
-#endif // MSHVIEW_H
diff --git a/Applications/DataExplorer/DataView/NetCdfConfigureDialog.h b/Applications/DataExplorer/DataView/NetCdfConfigureDialog.h
index 7e4d500abd0a2a488608519ef2187e5f5103b03c..6371f44127d85714bf6237f43fa74c139c45ae22 100644
--- a/Applications/DataExplorer/DataView/NetCdfConfigureDialog.h
+++ b/Applications/DataExplorer/DataView/NetCdfConfigureDialog.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NETCDFCONFIGUREDIALOG_H
-#define NETCDFCONFIGUREDIALOG_H
+#pragma once
 
 #include <netcdfcpp.h>
 
@@ -73,6 +72,3 @@ private:
     std::string _currentPath;
     std::vector<int> _id_map;
 };
-
-#endif //NETCDFCONFIGUREDIALOG_H
-
diff --git a/Applications/DataExplorer/DataView/SHPImportDialog.h b/Applications/DataExplorer/DataView/SHPImportDialog.h
index 204a86d238c02ce4729ccbf36fcfaaddcc14c4c9..2b67a363c5d7d0f8726075cae9a6e30989925813 100644
--- a/Applications/DataExplorer/DataView/SHPImportDialog.h
+++ b/Applications/DataExplorer/DataView/SHPImportDialog.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef SHPIMPORTDIALOG_H
-#define SHPIMPORTDIALOG_H
+#pragma once
 
 #include <QDialog>
 
@@ -71,5 +70,3 @@ private slots:
 signals:
     void shpLoaded(QString);
 };
-
-#endif //SHPIMPORTDIALOG_H
diff --git a/Applications/DataExplorer/DataView/SaveMeshDialog.h b/Applications/DataExplorer/DataView/SaveMeshDialog.h
index 2e0dcd5982c76104b7d0b6ba590f271e4919d650..0e371636be7e7bc495298c2d887b8a342e8eea75 100644
--- a/Applications/DataExplorer/DataView/SaveMeshDialog.h
+++ b/Applications/DataExplorer/DataView/SaveMeshDialog.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef SAVEMESHDIALOG_H
-#define SAVEMESHDIALOG_H
+#pragma once
 
 #include "ui_SaveMesh.h"
 #include <QDialog>
@@ -49,5 +48,3 @@ private:
     MeshLib::Mesh const& _mesh;
 
 };
-
-#endif //SAVEMESHDIALOG_H
diff --git a/Applications/DataExplorer/DataView/SelectMeshDialog.h b/Applications/DataExplorer/DataView/SelectMeshDialog.h
index 72d037a2b2ca8185d53f46aee3e4e34efa54954a..dcc1c4e1f94938f324e95cdb389e2b2ea9cc3385 100644
--- a/Applications/DataExplorer/DataView/SelectMeshDialog.h
+++ b/Applications/DataExplorer/DataView/SelectMeshDialog.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef SELECTMESHDIALOG_H
-#define SELECTMESHDIALOG_H
+#pragma once
 
 #include <QDialog>
 
@@ -62,5 +61,3 @@ private slots:
 signals:
     //void requestNameChange(const std::string&, const GeoLib::GEOTYPE, std::size_t, std::string);
 };
-
-#endif //SELECTMESHDIALOG_H
diff --git a/Applications/DataExplorer/DataView/SetNameDialog.h b/Applications/DataExplorer/DataView/SetNameDialog.h
index 3c71dd2504176891c5156ba29e33c6600444a3c6..5afe0ea52d4368ae1bc8e780264e824d75a5eedd 100644
--- a/Applications/DataExplorer/DataView/SetNameDialog.h
+++ b/Applications/DataExplorer/DataView/SetNameDialog.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef SETNAMEDIALOG_H
-#define SETNAMEDIALOG_H
+#pragma once
 
 #include "GeoType.h"
 
@@ -54,5 +53,3 @@ private slots:
     /// Instructions if the Cancel-Button has been pressed.
     void reject();
 };
-
-#endif //SETNAMEDIALOG_H
diff --git a/Applications/DataExplorer/DataView/StationTabWidget.h b/Applications/DataExplorer/DataView/StationTabWidget.h
index 2c16648fced25a7ab8b974c00d8adf629c1f3847..2cfefb80502ec26cdb05144bde582d2d38523fb0 100644
--- a/Applications/DataExplorer/DataView/StationTabWidget.h
+++ b/Applications/DataExplorer/DataView/StationTabWidget.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef STATIONTABWIDGET_H
-#define STATIONTABWIDGET_H
+#pragma once
 
 // ** INCLUDES **
 #include "ui_StationTabWidgetBase.h"
@@ -34,5 +33,3 @@ private slots:
     void enableSaveButton(bool enable) { this->saveStnPushButton->setEnabled(enable); };
     void enableRemoveButton(bool enable) { this->removeStnPushButton->setEnabled(enable); };
 };
-
-#endif // STATIONTABWIDGET_H
diff --git a/Applications/DataExplorer/DataView/StationTreeModel.h b/Applications/DataExplorer/DataView/StationTreeModel.h
index 3af6c01a3a3d923a0453e77d19ee8bd93a26967e..a303250304a768eeb14f82ff6ce95e68a0c1ba01 100644
--- a/Applications/DataExplorer/DataView/StationTreeModel.h
+++ b/Applications/DataExplorer/DataView/StationTreeModel.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef QSTATIONTREEMODEL_H
-#define QSTATIONTREEMODEL_H
+#pragma once
 
 #include <vector>
 
@@ -61,5 +60,3 @@ public:
 private:
     std::vector<ModelTreeItem*> _lists;
 };
-
-#endif //QSTATIONTREEMODEL_H
diff --git a/Applications/DataExplorer/DataView/StationTreeView.h b/Applications/DataExplorer/DataView/StationTreeView.h
index 1ac4339e85ec4b46370f31420bf152a894dd8e67..3b5ed7c73e3b526c7e44d3b45213aac92684b2c5 100644
--- a/Applications/DataExplorer/DataView/StationTreeView.h
+++ b/Applications/DataExplorer/DataView/StationTreeView.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef QSTATIONTREEVIEW_H
-#define QSTATIONTREEVIEW_H
+#pragma once
 
 #include "Station.h"
 
@@ -81,5 +80,3 @@ signals:
     void stationListSaved(QString listName, QString fileName);
     void diagramRequested(QModelIndex&);
 };
-
-#endif //QSTATIONTREEVIEW_H
diff --git a/Applications/DataExplorer/DataView/StratView/StratBar.h b/Applications/DataExplorer/DataView/StratView/StratBar.h
index fe118bb114f7a39fec0b6e514494d04d228d3913..66b39987ab20ea4468161e92cbd7617016861ecd 100644
--- a/Applications/DataExplorer/DataView/StratView/StratBar.h
+++ b/Applications/DataExplorer/DataView/StratView/StratBar.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef STRATBAR_H
-#define STRATBAR_H
+#pragma once
 
 #include <cmath>
 
@@ -63,5 +62,3 @@ private:
     GeoLib::StationBorehole* _station;
     std::map<std::string, DataHolderLib::Color> _stratColors;
 };
-
-#endif //STRATBAR_H
diff --git a/Applications/DataExplorer/DataView/StratView/StratScene.h b/Applications/DataExplorer/DataView/StratView/StratScene.h
index 1bf01aa337fbfa84fc2082ed1b5ba8940a71d14b..03fb668834335cb265190715b55f57017156c65d 100644
--- a/Applications/DataExplorer/DataView/StratView/StratScene.h
+++ b/Applications/DataExplorer/DataView/StratView/StratScene.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef STRATSCENE_H
-#define STRATSCENE_H
+#pragma once
 
 #include <QGraphicsScene>
 
@@ -55,5 +54,3 @@ private:
     StratBar* addStratBar(GeoLib::StationBorehole* station,
                           std::map<std::string, DataHolderLib::Color>* stratColors = nullptr);
 };
-
-#endif //STRATSCENE_H
diff --git a/Applications/DataExplorer/DataView/StratView/StratView.h b/Applications/DataExplorer/DataView/StratView/StratView.h
index 87c61dd66029d2c2b9a570be556461f97f29990c..b55b30db4eb436cfd4281c84c23d13d9e41d0257 100644
--- a/Applications/DataExplorer/DataView/StratView/StratView.h
+++ b/Applications/DataExplorer/DataView/StratView/StratView.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef STRATVIEW_H
-#define STRATVIEW_H
+#pragma once
 
 #include "StratScene.h"
 #include <QGraphicsView>
@@ -69,5 +68,3 @@ private:
 
     StratScene* _scene;
 };
-
-#endif //STRATVIEW_H
diff --git a/Applications/DataExplorer/DataView/StratView/StratWindow.h b/Applications/DataExplorer/DataView/StratView/StratWindow.h
index d3f235ad38f793cc79f965d83c4bb6d8c5335451..16da35d466fd9ed4b98ee03533571a8c727a70a1 100644
--- a/Applications/DataExplorer/DataView/StratView/StratWindow.h
+++ b/Applications/DataExplorer/DataView/StratView/StratWindow.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef STRATWINDOW_H
-#define STRATWINDOW_H
+#pragma once
 
 #include "ui_StratWindow.h"
 #include <QWidget>
@@ -49,5 +48,3 @@ private:
 private slots:
     void on_closeButton_clicked();
 };
-
-#endif //STRATWINDOW_H
diff --git a/Applications/DataExplorer/DataView/SurfaceExtractionDialog.h b/Applications/DataExplorer/DataView/SurfaceExtractionDialog.h
index af3fa26df1c945ff8b9d8f6a539c0606ff61c590..ad482c3b457ec8a9c7067e08fe61cbb399bfd93b 100644
--- a/Applications/DataExplorer/DataView/SurfaceExtractionDialog.h
+++ b/Applications/DataExplorer/DataView/SurfaceExtractionDialog.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef SURFACEEXTRACTIONDIALOG_H
-#define SURFACEEXTRACTIONDIALOG_H
+#pragma once
 
 #include "ui_SurfaceExtraction.h"
 #include <QDialog>
@@ -49,5 +48,3 @@ private:
     int _tolerance;
     MathLib::Vector3 _dir;
 };
-
-#endif //SURFACEEXTRACTIONDIALOG_H
diff --git a/Applications/DataExplorer/VtkAct/VtkCustomInteractorStyle.h b/Applications/DataExplorer/VtkAct/VtkCustomInteractorStyle.h
index 23680e6b7537125e608068e098eb61a1a4c92913..04b480b6515163d978b55c34cb6dbd8e2355ea03 100644
--- a/Applications/DataExplorer/VtkAct/VtkCustomInteractorStyle.h
+++ b/Applications/DataExplorer/VtkAct/VtkCustomInteractorStyle.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKCUSTOMINTERACTORSTYLE_H
-#define VTKCUSTOMINTERACTORSTYLE_H
+#pragma once
 
 // ** INCLUDES **
 #include <QObject>
@@ -99,6 +98,3 @@ signals:
     void clearElementView();
 
 };
-
-
-#endif // VTKINTERACTORSTYLE_H
diff --git a/Applications/DataExplorer/VtkAct/VtkPickCallback.h b/Applications/DataExplorer/VtkAct/VtkPickCallback.h
index 774e7f2d81696eda60a2713124d7edec6135377c..baaaf9e8b9cfc7ac49bb8b63077c826353192773 100644
--- a/Applications/DataExplorer/VtkAct/VtkPickCallback.h
+++ b/Applications/DataExplorer/VtkAct/VtkPickCallback.h
@@ -13,8 +13,7 @@
  *
  */
 
-#ifndef VTKPICKCALLBACK_H
-#define VTKPICKCALLBACK_H
+#pragma once
 
 // ** INCLUDES **
 #include <QObject>
@@ -42,5 +41,3 @@ signals:
     /// Is emitted when an vtkActor was picked.
     void actorPicked (vtkProp3D* actor);
 };
-
-#endif // VTKPICKCALLBACK_H
diff --git a/Applications/DataExplorer/VtkVis/MeshFromRasterDialog.h b/Applications/DataExplorer/VtkVis/MeshFromRasterDialog.h
index 80d69a9889246b4c0af8bdbeab3332f7982045fa..e474792a216fd377f608970cbedffbfd4d148977 100644
--- a/Applications/DataExplorer/VtkVis/MeshFromRasterDialog.h
+++ b/Applications/DataExplorer/VtkVis/MeshFromRasterDialog.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef MSHFROMRASTERDIALOG_H
-#define MSHFROMRASTERDIALOG_H
+#pragma once
 
 #include "ui_MeshFromRaster.h"
 
@@ -57,5 +56,3 @@ private:
     MeshLib::UseIntensityAs _intensity_selection;
 
 };
-
-#endif //MSHFROMRASTERDIALOG_H
diff --git a/Applications/DataExplorer/VtkVis/OGSFilterInfo.h b/Applications/DataExplorer/VtkVis/OGSFilterInfo.h
index f21c9bcff4ffd78cc8f36a715b7f9eaf05ba0342..ec99f44a0c0aae0d27058107c20c2a757f1699bd 100644
--- a/Applications/DataExplorer/VtkVis/OGSFilterInfo.h
+++ b/Applications/DataExplorer/VtkVis/OGSFilterInfo.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef OGSFILTERINFO_H
-#define OGSFILTERINFO_H
+#pragma once
 
 #include "VtkOGSFilter.h"
 #include <string>
@@ -41,5 +40,3 @@ private:
     VtkOGSFilter::OGSVisFilter _filter;
     VtkTargetObject _target;
 };
-
-#endif // OGSFILTERINFO_H
diff --git a/Applications/DataExplorer/VtkVis/QVtkDataSetMapper.h b/Applications/DataExplorer/VtkVis/QVtkDataSetMapper.h
index 30419cf90c7dd2817fd092945da11b494d262324..596782ba698ca1db6fa205d8d8c3f998e6431ab4 100644
--- a/Applications/DataExplorer/VtkVis/QVtkDataSetMapper.h
+++ b/Applications/DataExplorer/VtkVis/QVtkDataSetMapper.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef QVTKDATASETMAPPER_H
-#define QVTKDATASETMAPPER_H
+#pragma once
 
 #include <QObject>
 #include <vtkDataSetMapper.h>
@@ -48,5 +47,3 @@ private:
     QVtkDataSetMapper(const QVtkDataSetMapper&); // Not implemented.
     void operator=(const QVtkDataSetMapper&); // Not implemented
 };
-
-#endif // QVTKDATASETMAPPER_H
diff --git a/Applications/DataExplorer/VtkVis/VisPrefsDialog.h b/Applications/DataExplorer/VtkVis/VisPrefsDialog.h
index 7bdcb96d53813926783ba343b0a826bbea385976..ac76e0d708c917b4019eff8d08eb08c127b1c2c5 100644
--- a/Applications/DataExplorer/VtkVis/VisPrefsDialog.h
+++ b/Applications/DataExplorer/VtkVis/VisPrefsDialog.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VISPREFSDIALOG_H
-#define VISPREFSDIALOG_H
+#pragma once
 
 #include "Point.h"
 #include "ui_VisPrefs.h"
@@ -59,5 +58,3 @@ private:
     GeoLib::Point _above;
     GeoLib::Point _below;
 };
-
-#endif //VISPREFSDIALOG_H
diff --git a/Applications/DataExplorer/VtkVis/VisualizationWidget.h b/Applications/DataExplorer/VtkVis/VisualizationWidget.h
index 21e57760d19e2f7e95b8ea96e08a249d55770a44..68aadb2abcf4f590a393955b0e22004a93c4cc69 100644
--- a/Applications/DataExplorer/VtkVis/VisualizationWidget.h
+++ b/Applications/DataExplorer/VtkVis/VisualizationWidget.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VISUALIZATIONWIDGET_H
-#define VISUALIZATIONWIDGET_H
+#pragma once
 
 // ** INCLUDES **
 #include "ui_VisualizationWidgetBase.h"
@@ -110,5 +109,3 @@ private:
     VtkPickCallback* _vtkPickCallback;
     bool _isShowAllOnLoad;
 };
-
-#endif // VISUALIZATIONWIDGET_H
diff --git a/Applications/DataExplorer/VtkVis/VtkAddFilterDialog.h b/Applications/DataExplorer/VtkVis/VtkAddFilterDialog.h
index 72e36ad60b68e1ceef94babdd9ccddd9fb9eedab..2086a34ed617c3b188c7bd57f1728b17e33e8bdc 100644
--- a/Applications/DataExplorer/VtkVis/VtkAddFilterDialog.h
+++ b/Applications/DataExplorer/VtkVis/VtkAddFilterDialog.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKADDFILTERDIALOG_H
-#define VTKADDFILTERDIALOG_H
+#pragma once
 
 // ** INCLUDES **
 #include "ui_VtkAddFilterDialogBase.h"
@@ -45,5 +44,3 @@ private:
     VtkVisPipeline& _pipeline;
     QModelIndex _parentIndex;
 };
-
-#endif // VTKADDFILTERDIALOG_H
diff --git a/Applications/DataExplorer/VtkVis/VtkAlgorithmProperties.h b/Applications/DataExplorer/VtkVis/VtkAlgorithmProperties.h
index 487425c24554d1cb33e8a74ae8ec0bcfe6d66d87..10dbe7a6bd8e6c5590049a4a5cfad7c9e27c5fe7 100644
--- a/Applications/DataExplorer/VtkVis/VtkAlgorithmProperties.h
+++ b/Applications/DataExplorer/VtkVis/VtkAlgorithmProperties.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKALGORITHMPROPERTIES_H
-#define VTKALGORITHMPROPERTIES_H
+#pragma once
 
 // ** INCLUDES **
 #include <QList>
@@ -235,5 +234,3 @@ protected:
 signals:
     void ScalarVisibilityChanged(bool on);
 };
-
-#endif // VTKALGORITHMPROPERTIES_H
diff --git a/Applications/DataExplorer/VtkVis/VtkAlgorithmPropertyCheckbox.h b/Applications/DataExplorer/VtkVis/VtkAlgorithmPropertyCheckbox.h
index 4db988b48b3a791d1dabbf4c0b98adaaf7eb8edb..3ed35df96e37b38e1b484e12202f750238be7c33 100644
--- a/Applications/DataExplorer/VtkVis/VtkAlgorithmPropertyCheckbox.h
+++ b/Applications/DataExplorer/VtkVis/VtkAlgorithmPropertyCheckbox.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKALGORITHMPROPERTIESCHECKBOX_H
-#define VTKALGORITHMPROPERTIESCHECKBOX_H
+#pragma once
 
 #include <QCheckBox>
 
@@ -45,5 +44,3 @@ private slots:
     /// @brief This slots is automatically called when the checkbox state changed.
     void setNewValue(int state);
 };
-
-#endif // VTKALGORITHMPROPERTIESCHECKBOX_H
diff --git a/Applications/DataExplorer/VtkVis/VtkAlgorithmPropertyLineEdit.h b/Applications/DataExplorer/VtkVis/VtkAlgorithmPropertyLineEdit.h
index 56f3c340d628bd2c4a73c70fe7fbfb18582f3546..6045b33e291b29f11d61ec44e99caefbf296f225 100644
--- a/Applications/DataExplorer/VtkVis/VtkAlgorithmPropertyLineEdit.h
+++ b/Applications/DataExplorer/VtkVis/VtkAlgorithmPropertyLineEdit.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKALGORITHMPROPERTYLINEEDIT_H
-#define VTKALGORITHMPROPERTYLINEEDIT_H
+#pragma once
 
 #include <QLineEdit>
 #include <QVariant>
@@ -50,5 +49,3 @@ private slots:
     /// @brief This slots is automatically called when the text changed.
     void setNewValue();
 };
-
-#endif // VTKALGORITHMPROPERTYLINEEDIT_H
diff --git a/Applications/DataExplorer/VtkVis/VtkAlgorithmPropertyVectorEdit.h b/Applications/DataExplorer/VtkVis/VtkAlgorithmPropertyVectorEdit.h
index cb78d0ff1cc5feda39ec0b47a68cbae6a95fa5ee..c697818960a5dcb5b8ddedcd0ba54cae3a9f2f37 100644
--- a/Applications/DataExplorer/VtkVis/VtkAlgorithmPropertyVectorEdit.h
+++ b/Applications/DataExplorer/VtkVis/VtkAlgorithmPropertyVectorEdit.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKALGORITHMPROPERTYVECTOREDIT_H
-#define VTKALGORITHMPROPERTYVECTOREDIT_H
+#pragma once
 
 #include <QList>
 #include <QVariant>
@@ -54,5 +53,3 @@ signals:
     /// @brief Is emitted when text of one the line edits changed.
     void editingFinished();
 };
-
-#endif // VTKALGORITHMPROPERTYVECTOREDIT_H
diff --git a/Applications/DataExplorer/VtkVis/VtkAppendArrayFilter.h b/Applications/DataExplorer/VtkVis/VtkAppendArrayFilter.h
index 604a0430709fdf2d12d4c8a972addcc189df259b..60ac3fb2410ed787e943eb70a8b1015242f6d16f 100644
--- a/Applications/DataExplorer/VtkVis/VtkAppendArrayFilter.h
+++ b/Applications/DataExplorer/VtkVis/VtkAppendArrayFilter.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKAPPENDARRAYFILTER_H
-#define VTKAPPENDARRAYFILTER_H
+#pragma once
 
 // ** INCLUDES **
 #include "VtkAlgorithmProperties.h"
@@ -58,5 +57,3 @@ private:
     std::vector<double> _array;
     std::string _array_name;
 };
-
-#endif // VTKAPPENDARRAYFILTER_H
diff --git a/Applications/DataExplorer/VtkVis/VtkBGImageSource.h b/Applications/DataExplorer/VtkVis/VtkBGImageSource.h
index 509164d8c333bcd0b23ecce803af092d37dde059..948aedc0889add8cc12292b002d746c9d372e79f 100644
--- a/Applications/DataExplorer/VtkVis/VtkBGImageSource.h
+++ b/Applications/DataExplorer/VtkVis/VtkBGImageSource.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKBGIMAGESOURCE_H
-#define VTKBGIMAGESOURCE_H
+#pragma once
 
 // ** INCLUDES **
 #include <vtkTextureMapToPlane.h>
@@ -48,5 +47,3 @@ private:
     std::pair<double, double> _origin;
     double _cellsize;
 };
-
-#endif // VTKBGIMAGESOURCE_H
diff --git a/Applications/DataExplorer/VtkVis/VtkColorByHeightFilter.h b/Applications/DataExplorer/VtkVis/VtkColorByHeightFilter.h
index 02b83c2418b2ff5922e22f456dc2756055fa91b2..6202918e8ce6364ec3091ea4d542bdcd7b72957f 100644
--- a/Applications/DataExplorer/VtkVis/VtkColorByHeightFilter.h
+++ b/Applications/DataExplorer/VtkVis/VtkColorByHeightFilter.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKCOLORBYHEIGHTFILTER_H
-#define VTKCOLORBYHEIGHTFILTER_H
+#pragma once
 
 // ** INCLUDES **
 #include "VtkAlgorithmProperties.h"
@@ -81,5 +80,3 @@ protected:
     double _tableRange[2];
     double _tableRangeScaling;
 };
-
-#endif // VTKCOLORBYHEIGHTFILTER_H
diff --git a/Applications/DataExplorer/VtkVis/VtkColorLookupTable.h b/Applications/DataExplorer/VtkVis/VtkColorLookupTable.h
index 88b5e028016ffe17cc1269d2378e6e139ffb3543..5b685fd1178dbc42ac46c9a6d90401272f5b897a 100644
--- a/Applications/DataExplorer/VtkVis/VtkColorLookupTable.h
+++ b/Applications/DataExplorer/VtkVis/VtkColorLookupTable.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKCOLORLOOKUPTABLE_H
-#define VTKCOLORLOOKUPTABLE_H
+#pragma once
 
 // ** INCLUDES **
 #include <cassert>
@@ -95,5 +94,3 @@ private:
     std::map<double, unsigned char*> _dict;
     DataHolderLib::LUTType _type;
 };
-
-#endif // VTKCOLORLOOKUPTABLE_H
diff --git a/Applications/DataExplorer/VtkVis/VtkCompositeColorByHeightFilter.h b/Applications/DataExplorer/VtkVis/VtkCompositeColorByHeightFilter.h
index 90db8eac7e9fac12187f01fc27aef88aeb11f967..220f31ac8e4243cacc8c0096fdbe3b743e7a9b19 100644
--- a/Applications/DataExplorer/VtkVis/VtkCompositeColorByHeightFilter.h
+++ b/Applications/DataExplorer/VtkVis/VtkCompositeColorByHeightFilter.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKCOMPOSITECOLORBYHEIGHTFILTER_H
-#define VTKCOMPOSITECOLORBYHEIGHTFILTER_H
+#pragma once
 
 #include "VtkCompositeFilter.h"
 
@@ -32,5 +31,3 @@ public:
 
 protected:
 };
-
-#endif // VTKCOMPOSITECOLORBYHEIGHTFILTER_H
diff --git a/Applications/DataExplorer/VtkVis/VtkCompositeColormapToImageFilter.h b/Applications/DataExplorer/VtkVis/VtkCompositeColormapToImageFilter.h
index caed44fda1aaf82418d1a35e9a76376ef516e5c0..68c33443216e5553deb37d64ef90bbc85917d939 100644
--- a/Applications/DataExplorer/VtkVis/VtkCompositeColormapToImageFilter.h
+++ b/Applications/DataExplorer/VtkVis/VtkCompositeColormapToImageFilter.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKCOMPOSITECOLORMAPTOIMAGEFILTER_H
-#define VTKCOMPOSITECOLORMAPTOIMAGEFILTER_H
+#pragma once
 
 #include "VtkCompositeFilter.h"
 
@@ -32,5 +31,3 @@ public:
 
 private:
 };
-
-#endif // VTKCOMPOSITECOLORMAPTOIMAGEFILTER_H
diff --git a/Applications/DataExplorer/VtkVis/VtkCompositeContourFilter.h b/Applications/DataExplorer/VtkVis/VtkCompositeContourFilter.h
index 727bd7215d5ae357eb46ff1da0efbade445da263..17349ba38afa470db32ea435c5c2950bb4327b2a 100644
--- a/Applications/DataExplorer/VtkVis/VtkCompositeContourFilter.h
+++ b/Applications/DataExplorer/VtkVis/VtkCompositeContourFilter.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKCOMPOSITECONTOURFILTER_H
-#define VTKCOMPOSITECONTOURFILTER_H
+#pragma once
 
 #include "VtkCompositeFilter.h"
 
@@ -34,5 +33,3 @@ public:
 
 private:
 };
-
-#endif // VTKCOMPOSITECONTOURFILTER_H
diff --git a/Applications/DataExplorer/VtkVis/VtkCompositeElementSelectionFilter.h b/Applications/DataExplorer/VtkVis/VtkCompositeElementSelectionFilter.h
index 168ae997ab84fd9ff3c438d81c9f26258c925611..12c9901ba702310c8fcb24e6917e6aa8e0751887 100644
--- a/Applications/DataExplorer/VtkVis/VtkCompositeElementSelectionFilter.h
+++ b/Applications/DataExplorer/VtkVis/VtkCompositeElementSelectionFilter.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKCOMPOSITESELECTIONFILTER_H
-#define VTKCOMPOSITESELECTIONFILTER_H
+#pragma once
 
 #include "VtkCompositeFilter.h"
 
@@ -47,5 +46,3 @@ private:
     std::string _selection_name;
     std::vector<double> _selection;
 };
-
-#endif // VTKCOMPOSITESELECTIONFILTER_H
diff --git a/Applications/DataExplorer/VtkVis/VtkCompositeFilter.h b/Applications/DataExplorer/VtkVis/VtkCompositeFilter.h
index 19e115fcfddeea1fb14cc3fcf171f8d230e06009..d475240b9194bf9f4e4acff4f36e7fe8e1e8ca6e 100644
--- a/Applications/DataExplorer/VtkVis/VtkCompositeFilter.h
+++ b/Applications/DataExplorer/VtkVis/VtkCompositeFilter.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKCOMPOSITEFILTER_H
-#define VTKCOMPOSITEFILTER_H
+#pragma once
 
 #include "VtkAlgorithmProperties.h"
 
@@ -80,5 +79,3 @@ protected:
 
     virtual void init() = 0;
 };
-
-#endif // VTKCOMPOSITEFILTER_H
diff --git a/Applications/DataExplorer/VtkVis/VtkCompositeGeoObjectFilter.h b/Applications/DataExplorer/VtkVis/VtkCompositeGeoObjectFilter.h
index a4e8abd306791447a7230594814caa2336e35e7b..ffada6a66532673a7b0311156f14ff41d3306338 100644
--- a/Applications/DataExplorer/VtkVis/VtkCompositeGeoObjectFilter.h
+++ b/Applications/DataExplorer/VtkVis/VtkCompositeGeoObjectFilter.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKCOMPOSITEGEOOBJECTFILTER_H
-#define VTKCOMPOSITEGEOOBJECTFILTER_H
+#pragma once
 
 #include "VtkCompositeFilter.h"
 #include "GeoType.h"
@@ -42,5 +41,3 @@ private:
     GeoLib::GEOTYPE _type;
     vtkThreshold* _threshold;
 };
-
-#endif // VTKCOMPOSITEGEOOBJECTFILTER_H
diff --git a/Applications/DataExplorer/VtkVis/VtkCompositeImageToCylindersFilter.h b/Applications/DataExplorer/VtkVis/VtkCompositeImageToCylindersFilter.h
index 595d96aacbfc36eec1374710f4e736334647cac4..53b73ec7c82b0c0d00ecf17d0adc00b7794dfce9 100644
--- a/Applications/DataExplorer/VtkVis/VtkCompositeImageToCylindersFilter.h
+++ b/Applications/DataExplorer/VtkVis/VtkCompositeImageToCylindersFilter.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKCOMPOSITEIMAGETOCYLINDERSFILTER_H
-#define VTKCOMPOSITEIMAGETOCYLINDERSFILTER_H
+#pragma once
 
 #include "VtkCompositeFilter.h"
 
@@ -37,5 +36,3 @@ public:
 private:
     VtkImageDataToLinePolyDataFilter* _lineFilter;
 };
-
-#endif // VTKCOMPOSITEIMAGETOCYLINDERSFILTER_H
diff --git a/Applications/DataExplorer/VtkVis/VtkCompositeLineToTubeFilter.h b/Applications/DataExplorer/VtkVis/VtkCompositeLineToTubeFilter.h
index 7b75246968d5515be208bf19657a820bcfd8f21e..68f4bae8ee6004995a6b0b61e034550bd7bbd719 100644
--- a/Applications/DataExplorer/VtkVis/VtkCompositeLineToTubeFilter.h
+++ b/Applications/DataExplorer/VtkVis/VtkCompositeLineToTubeFilter.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKCOMPOSITELINETOTUBEFILTER_H
-#define VTKCOMPOSITELINETOTUBEFILTER_H
+#pragma once
 
 #include "VtkCompositeFilter.h"
 
@@ -31,5 +30,3 @@ public:
 private:
 
 };
-
-#endif // VTKCOMPOSITELINETOTUBEFILTER_H
diff --git a/Applications/DataExplorer/VtkVis/VtkCompositeNodeSelectionFilter.h b/Applications/DataExplorer/VtkVis/VtkCompositeNodeSelectionFilter.h
index faca42688e12e3aacfa2b3f5a126a23b810bd7bc..d3dce1d7d4342903e88b21589e0dcc746b718293 100644
--- a/Applications/DataExplorer/VtkVis/VtkCompositeNodeSelectionFilter.h
+++ b/Applications/DataExplorer/VtkVis/VtkCompositeNodeSelectionFilter.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKCOMPOSITENODESELECTIONFILTER_H
-#define VTKCOMPOSITENODESELECTIONFILTER_H
+#pragma once
 
 #include "VtkCompositeFilter.h"
 #include "Point.h"
@@ -35,5 +34,3 @@ public:
 private:
     std::vector<GeoLib::Point*> _selection;
 };
-
-#endif // VTKCOMPOSITENODESELECTIONFILTER_H
diff --git a/Applications/DataExplorer/VtkVis/VtkCompositePointToGlyphFilter.h b/Applications/DataExplorer/VtkVis/VtkCompositePointToGlyphFilter.h
index cbb0f58f70ba6c3297656002b53cb6b0a98ca587..4e277040a5537824d28cc20e17bd1d67d9f0687a 100644
--- a/Applications/DataExplorer/VtkVis/VtkCompositePointToGlyphFilter.h
+++ b/Applications/DataExplorer/VtkVis/VtkCompositePointToGlyphFilter.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKCOMPOSITEPOINTTOGLYPHFILTER_H
-#define VTKCOMPOSITEPOINTTOGLYPHFILTER_H
+#pragma once
 
 #include "VtkCompositeFilter.h"
 
@@ -33,5 +32,3 @@ public:
 private:
     vtkSphereSource* _glyphSource;
 };
-
-#endif // VTKCOMPOSITEPOINTTOGLYPHFILTER_H
diff --git a/Applications/DataExplorer/VtkVis/VtkCompositeTextureOnSurfaceFilter.h b/Applications/DataExplorer/VtkVis/VtkCompositeTextureOnSurfaceFilter.h
index b704418938c7269749ae30b9e3439147971103fe..98eef699b2e0cb9c924b09c9b2ca730be82f9a65 100644
--- a/Applications/DataExplorer/VtkVis/VtkCompositeTextureOnSurfaceFilter.h
+++ b/Applications/DataExplorer/VtkVis/VtkCompositeTextureOnSurfaceFilter.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKCOMPOSITETEXTUREONSURFACEFILTER_H
-#define VTKCOMPOSITETEXTUREONSURFACEFILTER_H
+#pragma once
 
 #include "VtkCompositeFilter.h"
 
@@ -32,5 +31,3 @@ public:
 
 private:
 };
-
-#endif // VTKCOMPOSITETEXTUREONSURFACEFILTER_H
diff --git a/Applications/DataExplorer/VtkVis/VtkCompositeThresholdFilter.h b/Applications/DataExplorer/VtkVis/VtkCompositeThresholdFilter.h
index a5ca60c2ffdfd5d0d4c038181d16933f0c1cb108..0e7556a17c3763218fa09942834b1fe9053c9684 100644
--- a/Applications/DataExplorer/VtkVis/VtkCompositeThresholdFilter.h
+++ b/Applications/DataExplorer/VtkVis/VtkCompositeThresholdFilter.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKCOMPOSITETHRESHOLDFILTER_H
-#define VTKCOMPOSITETHRESHOLDFILTER_H
+#pragma once
 
 #include "VtkCompositeFilter.h"
 
@@ -34,5 +33,3 @@ public:
 
 private:
 };
-
-#endif // VTKCOMPOSITETHRESHOLDFILTER_H
diff --git a/Applications/DataExplorer/VtkVis/VtkConsoleOutputWindow.h b/Applications/DataExplorer/VtkVis/VtkConsoleOutputWindow.h
index d7012ce7c566761605cdd555e21ab6a3b5127c2d..5cf19696cca3c746208c38b503a50f7b5a0707f2 100644
--- a/Applications/DataExplorer/VtkVis/VtkConsoleOutputWindow.h
+++ b/Applications/DataExplorer/VtkVis/VtkConsoleOutputWindow.h
@@ -9,8 +9,7 @@
 *
 */
 
-#ifndef VTKCONSOLEOUTPUTWINDOW_H_
-#define VTKCONSOLEOUTPUTWINDOW_H_
+#pragma once
 
 #include "vtkOutputWindow.h"
 
@@ -34,5 +33,3 @@ private:
     VtkConsoleOutputWindow(const VtkConsoleOutputWindow &);  // Not implemented.
     void operator=(const VtkConsoleOutputWindow &);  // Not implemented.
 };
-
-#endif // VTKCONSOLEOUTPUTWINDOW_H_
diff --git a/Applications/DataExplorer/VtkVis/VtkFilterFactory.h b/Applications/DataExplorer/VtkVis/VtkFilterFactory.h
index 53d610773c005c53bd88c6991e39082f6c553e64..0007ea077c591949bdec293c53986d3eaffb469f 100644
--- a/Applications/DataExplorer/VtkVis/VtkFilterFactory.h
+++ b/Applications/DataExplorer/VtkVis/VtkFilterFactory.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKFILTERFACTORY_H
-#define VTKFILTERFACTORY_H
+#pragma once
 
 #include <QString>
 #include <QVector>
@@ -93,5 +92,3 @@ struct VtkFilterInfo
     int inputDataObjectType;
     int outputDataObjectType;
 };
-
-#endif // VTKFILTERFACTORY_H
diff --git a/Applications/DataExplorer/VtkVis/VtkGeoImageSource.h b/Applications/DataExplorer/VtkVis/VtkGeoImageSource.h
index 6f9fb6c28250e39b565ffc8ed4bbd29eefbce02f..93a72a95e7206c975d258349ab3eb1d5880881af 100644
--- a/Applications/DataExplorer/VtkVis/VtkGeoImageSource.h
+++ b/Applications/DataExplorer/VtkVis/VtkGeoImageSource.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKGEOIMAGESOURCE_H
-#define VTKGEOIMAGESOURCE_H
+#pragma once
 
 #include "VtkAlgorithmProperties.h"
 #include <vtkSimpleImageToImageFilter.h>
@@ -77,5 +76,3 @@ private:
 
     double _x0, _y0, _z0, _spacing;
 };
-
-#endif // VTKGEOIMAGESOURCE_H
diff --git a/Applications/DataExplorer/VtkVis/VtkImageDataToLinePolyDataFilter.h b/Applications/DataExplorer/VtkVis/VtkImageDataToLinePolyDataFilter.h
index 7155829afe8c850cfab8a7afaf0d5d65b480ae48..2cc7247e594bf59949720f72d17783d3c9b2c452 100644
--- a/Applications/DataExplorer/VtkVis/VtkImageDataToLinePolyDataFilter.h
+++ b/Applications/DataExplorer/VtkVis/VtkImageDataToLinePolyDataFilter.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKIMAGEDATATOLINEPOLYDATAFILTER_H
-#define VTKIMAGEDATATOLINEPOLYDATAFILTER_H
+#pragma once
 
 #include "VtkAlgorithmProperties.h"
 #include <vtkPolyDataAlgorithm.h>
@@ -70,5 +69,3 @@ private:
     VtkImageDataToLinePolyDataFilter(const VtkImageDataToLinePolyDataFilter&); // Not implemented.
     void operator=(const VtkImageDataToLinePolyDataFilter&); // Not implemented
 };
-
-#endif // VTKIMAGEDATATOLINEPOLYDATAFILTER_H
diff --git a/Applications/DataExplorer/VtkVis/VtkPointsSource.h b/Applications/DataExplorer/VtkVis/VtkPointsSource.h
index 640d5ade9bf5fd0725e8e327796b87048902855d..a9e50ddca5053002f54eb08b26845a81fec61c00 100644
--- a/Applications/DataExplorer/VtkVis/VtkPointsSource.h
+++ b/Applications/DataExplorer/VtkVis/VtkPointsSource.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKPOINTSSOURCE_H
-#define VTKPOINTSSOURCE_H
+#pragma once
 
 // ** INCLUDES **
 #include "VtkAlgorithmProperties.h"
@@ -60,5 +59,3 @@ protected:
 
 private:
 };
-
-#endif // VTKPOINTSSOURCE_H
diff --git a/Applications/DataExplorer/VtkVis/VtkPolylinesSource.h b/Applications/DataExplorer/VtkVis/VtkPolylinesSource.h
index ff071cc83b0ceb6551cb734f9791d0c660cc9b82..b8e03bc8329ef3240373199bedbbf38a21163dda 100644
--- a/Applications/DataExplorer/VtkVis/VtkPolylinesSource.h
+++ b/Applications/DataExplorer/VtkVis/VtkPolylinesSource.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKPOLYLINESSOURCE_H
-#define VTKPOLYLINESSOURCE_H
+#pragma once
 
 // ** INCLUDES **
 #include "VtkAlgorithmProperties.h"
@@ -63,5 +62,3 @@ protected:
 
 private:
 };
-
-#endif // VTKPOLYLINESSOURCE_H
diff --git a/Applications/DataExplorer/VtkVis/VtkRaster.h b/Applications/DataExplorer/VtkVis/VtkRaster.h
index bb7f1f92308d30e018e2f3e9d42e783d766870e8..74a8fbcb85753cf3e5df7ee8de677c070991f747 100644
--- a/Applications/DataExplorer/VtkVis/VtkRaster.h
+++ b/Applications/DataExplorer/VtkVis/VtkRaster.h
@@ -11,8 +11,7 @@
  *              http://www.opengeosys.org/project/license
  *
  */
-#ifndef VTKRASTER_H
-#define VTKRASTER_H
+#pragma once
 
 #include <string>
 #include "GeoLib/Raster.h"
@@ -73,5 +72,3 @@ private:
     /// Converts an uint32-number into a quadruple representing RGBA-colours for a pixel.
     static void uint32toRGBA(const unsigned int s, int* p);
 };
-
-#endif //VTKRASTER_H
diff --git a/Applications/DataExplorer/VtkVis/VtkStationSource.h b/Applications/DataExplorer/VtkVis/VtkStationSource.h
index 1f5417d506e5fd458b0dd5a532faa8a389b71ed0..da7e561984000a4c1dd3fd80c163eb0d928a93cb 100644
--- a/Applications/DataExplorer/VtkVis/VtkStationSource.h
+++ b/Applications/DataExplorer/VtkVis/VtkStationSource.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKSTATIONSOURCE_H
-#define VTKSTATIONSOURCE_H
+#pragma once
 
 #include <vtkPolyDataAlgorithm.h>
 
@@ -77,5 +76,3 @@ private:
 
     std::map<std::string, vtkIdType> _id_map;
 };
-
-#endif // VTKSTATIONSOURCE_H
diff --git a/Applications/DataExplorer/VtkVis/VtkSurfacesSource.h b/Applications/DataExplorer/VtkVis/VtkSurfacesSource.h
index c385ef495c1d5349333afabd8c52bc3314791369..f3b3b21e51718e84d263f40a85389bdfad976ef1 100644
--- a/Applications/DataExplorer/VtkVis/VtkSurfacesSource.h
+++ b/Applications/DataExplorer/VtkVis/VtkSurfacesSource.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKSURFACESSOURCE_H
-#define VTKSURFACESSOURCE_H
+#pragma once
 
 // ** INCLUDES **
 #include "VtkAlgorithmProperties.h"
@@ -64,5 +63,3 @@ protected:
 
 private:
 };
-
-#endif // VTKSURFACESSOURCE_H
diff --git a/Applications/DataExplorer/VtkVis/VtkTextureOnSurfaceFilter.h b/Applications/DataExplorer/VtkVis/VtkTextureOnSurfaceFilter.h
index 9298553589bc0a28ee026c97bd42625f06b76d5b..0fb02d095e2a71d8b571666278165b966bfa2653 100644
--- a/Applications/DataExplorer/VtkVis/VtkTextureOnSurfaceFilter.h
+++ b/Applications/DataExplorer/VtkVis/VtkTextureOnSurfaceFilter.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKOGSPOLYDATAALGORITHM_H
-#define VTKOGSPOLYDATAALGORITHM_H
+#pragma once
 
 // ** INCLUDES **
 #include "VtkAlgorithmProperties.h"
@@ -65,5 +64,3 @@ private:
     std::pair<float, float> _origin;
     double _scalingFactor;
 };
-
-#endif // VTKOGSPOLYDATAALGORITHM_H
diff --git a/Applications/DataExplorer/VtkVis/VtkVisHelper.h b/Applications/DataExplorer/VtkVis/VtkVisHelper.h
index 8561fe593dc8c1a34a715a161eb06875ae2dca9b..1ba17e910393d5a4bc2826a5ed57ddf961e2777e 100644
--- a/Applications/DataExplorer/VtkVis/VtkVisHelper.h
+++ b/Applications/DataExplorer/VtkVis/VtkVisHelper.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKVISHELPER_H
-#define VTKVISHELPER_H
+#pragma once
 
 class QImage;
 class vtkTexture;
@@ -31,5 +30,3 @@ public:
     /// @brief Converts a QImage-object into a vtkTexture-object
     static vtkTexture* QImageToVtkTexture(QImage &img);
 };
-
-#endif // VTKVISHELPER_H
diff --git a/Applications/DataExplorer/VtkVis/VtkVisImageItem.h b/Applications/DataExplorer/VtkVis/VtkVisImageItem.h
index d0f1bd91af17c466df7d5f4f5f8e0f854dd9435f..e24a9098d9457133bcce14a1e94fc4225222b65c 100644
--- a/Applications/DataExplorer/VtkVis/VtkVisImageItem.h
+++ b/Applications/DataExplorer/VtkVis/VtkVisImageItem.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKVISIMAGEITEM_H
-#define VTKVISIMAGEITEM_H
+#pragma once
 
 // ** INCLUDES **
 #include "VtkVisPipelineItem.h"
@@ -64,5 +63,3 @@ protected:
 private:
     vtkImageChangeInformation* _transformFilter;
 };
-
-#endif // VTKVISIMAGEITEM_H
diff --git a/Applications/DataExplorer/VtkVis/VtkVisPipeline.h b/Applications/DataExplorer/VtkVis/VtkVisPipeline.h
index e3589de1a9118bbbe8774cc930c6ee929334c026..4c49675531117003d7db22c8fb01ce095c16945d 100644
--- a/Applications/DataExplorer/VtkVis/VtkVisPipeline.h
+++ b/Applications/DataExplorer/VtkVis/VtkVisPipeline.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKVISPIPELINE_H
-#define VTKVISPIPELINE_H
+#pragma once
 
 #include <QMap>
 #include <QVector>
@@ -149,5 +148,3 @@ signals:
     void vtkVisPipelineChanged() const;
     void itemSelected(const QModelIndex&) const;
 };
-
-#endif // VTKVISPIPELINE_H
diff --git a/Applications/DataExplorer/VtkVis/VtkVisPipelineItem.h b/Applications/DataExplorer/VtkVis/VtkVisPipelineItem.h
index 1a7ff3b53f3f01d5f4e5d869c4ba0eb5e669de45..e0393d886a05c9e465ff6427d6de258811fd42c2 100644
--- a/Applications/DataExplorer/VtkVis/VtkVisPipelineItem.h
+++ b/Applications/DataExplorer/VtkVis/VtkVisPipelineItem.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKVISPIPELINEITEM_H
-#define VTKVISPIPELINEITEM_H
+#pragma once
 
 // ** INCLUDES **
 #include "BuildInfo.h"
@@ -147,5 +146,3 @@ protected:
 
 private:
 };
-
-#endif // VTKVISPIPELINEITEM_H
diff --git a/Applications/DataExplorer/VtkVis/VtkVisPipelineView.h b/Applications/DataExplorer/VtkVis/VtkVisPipelineView.h
index 0b0228503c661831a1679e0082e2ee955ed20611..cf93faf6725754b330d71e4f077d57b5e2959956 100644
--- a/Applications/DataExplorer/VtkVis/VtkVisPipelineView.h
+++ b/Applications/DataExplorer/VtkVis/VtkVisPipelineView.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKVISPIPELINEVIEW_H
-#define VTKVISPIPELINEVIEW_H
+#pragma once
 
 // ** INCLUDES **
 #include <QTreeView>
@@ -88,5 +87,3 @@ signals:
     void dataObjectSelected(vtkDataObject*);
     void meshAdded(MeshLib::Mesh*);
 };
-
-#endif // VTKVISPIPELINEVIEW_H
diff --git a/Applications/DataExplorer/VtkVis/VtkVisPointSetItem.h b/Applications/DataExplorer/VtkVis/VtkVisPointSetItem.h
index 8f9f4b95106c774a03d4d5d7f4f4e711bdb26899..3c5e37d15ea9ea398e3e46f1633a4a158200f9e8 100644
--- a/Applications/DataExplorer/VtkVis/VtkVisPointSetItem.h
+++ b/Applications/DataExplorer/VtkVis/VtkVisPointSetItem.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTKVISPOINTSETITEM_H
-#define VTKVISPOINTSETITEM_H
+#pragma once
 
 // ** INCLUDES **
 #include "VtkVisPipelineItem.h"
@@ -95,5 +94,3 @@ private:
     bool activeAttributeExists(vtkDataSetAttributes* data, std::string& name);
 
 };
-
-#endif // VTKVISPOINTSETITEM_H
diff --git a/Applications/DataExplorer/VtkVis/VtkVisTabWidget.h b/Applications/DataExplorer/VtkVis/VtkVisTabWidget.h
index 6a9358816145b979f0f55472d6b969397bd61de4..d815a25ecc762b6bbf25a59121e5f44272fced34 100644
--- a/Applications/DataExplorer/VtkVis/VtkVisTabWidget.h
+++ b/Applications/DataExplorer/VtkVis/VtkVisTabWidget.h
@@ -13,8 +13,7 @@
  *
  */
 
-#ifndef VTKVISTABWIDGET_H
-#define VTKVISTABWIDGET_H
+#pragma once
 
 // ** INCLUDES **
 #include "ui_VtkVisTabWidgetBase.h"
@@ -76,5 +75,3 @@ signals:
     /// Is emitted when a property was changed.
     void requestViewUpdate();
 };
-
-#endif // VTKVISTABWIDGET_H
diff --git a/Applications/DataExplorer/mainwindow.h b/Applications/DataExplorer/mainwindow.h
index c09d1294a44e801aea05cce8447448bc55ad417a..e1fc2fb9153f0354c7dd60be620f5e0af9c34f9d 100644
--- a/Applications/DataExplorer/mainwindow.h
+++ b/Applications/DataExplorer/mainwindow.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef MAINWINDOW_H
-#define MAINWINDOW_H
+#pragma once
 
 #include <memory>
 
@@ -156,5 +155,3 @@ public:
         qapp->exec();
     }
 };
-
-#endif // MAINWINDOW_H
diff --git a/Applications/DataHolderLib/Color.h b/Applications/DataHolderLib/Color.h
index 07c421ef3aab9f6d0d97d66441bf10dfc52bba16..bce09bb8309881d21b6e3264b2803456ff51dc0b 100644
--- a/Applications/DataHolderLib/Color.h
+++ b/Applications/DataHolderLib/Color.h
@@ -13,8 +13,7 @@
  *
  */
 
-#ifndef COLOR_H_
-#define COLOR_H_
+#pragma once
 
 #include <array>
 #include <map>
@@ -38,5 +37,3 @@ Color const getColor(const std::string &id, std::map<std::string, DataHolderLib:
 /// Convenience function to use the getColor method with numbers as identifiers.
 Color const getColor(double id, std::map<std::string, DataHolderLib::Color> &colors);
 } // namespace
-
-#endif /* COLOR_H_ */
diff --git a/Applications/DataHolderLib/ColorLookupTable.h b/Applications/DataHolderLib/ColorLookupTable.h
index da3e29708375da776ae57017f25360d71fdb650b..f71c178134c9b523a45ee13f16a0ba48e101eba1 100644
--- a/Applications/DataHolderLib/ColorLookupTable.h
+++ b/Applications/DataHolderLib/ColorLookupTable.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef COLORLOOKUPTABLE_H
-#define COLORLOOKUPTABLE_H
+#pragma once
 
 #include <cassert>
 #include <tuple>
@@ -67,5 +66,3 @@ private:
 };
 
 } // namespace
-
-#endif //COLORLOOKUPTABLE_H
diff --git a/Applications/DataHolderLib/Project.h b/Applications/DataHolderLib/Project.h
index 7f240e6a6aa1d5357ad9e07d9a48378c5f2d6c26..c3087039695b6677a9b91ea1128ab6943f56fdec 100644
--- a/Applications/DataHolderLib/Project.h
+++ b/Applications/DataHolderLib/Project.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef DATAEXPLORERPROJECT_H_
-#define DATAEXPLORERPROJECT_H_
+#pragma once
 
 #include <memory>
 
@@ -81,5 +80,3 @@ private:
 };
 
 } // namespace
-
-#endif //DATAEXPLORERPROJECT_H_
diff --git a/Applications/FileIO/AsciiRasterInterface.h b/Applications/FileIO/AsciiRasterInterface.h
index cf653a9f4e69eca351a9ebc62984f41c9b7037a1..baa80fb9e17135dbfce262dd2ca74cc70f316028 100644
--- a/Applications/FileIO/AsciiRasterInterface.h
+++ b/Applications/FileIO/AsciiRasterInterface.h
@@ -11,8 +11,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef ASCIIRASTERINTERFACE_H_
-#define ASCIIRASTERINTERFACE_H_
+#pragma once
 
 #include <fstream>
 #include <vector>
@@ -57,5 +56,3 @@ private:
 boost::optional<std::vector<GeoLib::Raster const*>> readRasters(
     std::vector<std::string> const& raster_paths);
 } // end namespace FileIO
-
-#endif /* ASCIIRASTERINTERFACE_H_ */
diff --git a/Applications/FileIO/CsvInterface.h b/Applications/FileIO/CsvInterface.h
index cca9cdc2b4b6fdcfe6912cd2be30ff41b1cc035d..fe87228764eb1fba16c25439711dbb5e638683dc 100644
--- a/Applications/FileIO/CsvInterface.h
+++ b/Applications/FileIO/CsvInterface.h
@@ -11,8 +11,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef CSVINTERFACE_H_
-#define CSVINTERFACE_H_
+#pragma once
 
 #include <logog/include/logog.hpp>
 #include <boost/any.hpp>
@@ -240,5 +239,3 @@ private:
 };
 
 } // FileIO
-
-#endif /* CSVINTERFACE_H_ */
diff --git a/Applications/FileIO/FEFLOW/FEFLOWGeoInterface.h b/Applications/FileIO/FEFLOW/FEFLOWGeoInterface.h
index 2c9079b8a9bee17112edcd177d14557d91b2a031..e98aa410e64e411ec34e2e53813fb70b12a6a34b 100644
--- a/Applications/FileIO/FEFLOW/FEFLOWGeoInterface.h
+++ b/Applications/FileIO/FEFLOW/FEFLOWGeoInterface.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef FEFLOWGEOINTERFACE_H_
-#define FEFLOWGEOINTERFACE_H_
+#pragma once
 
 #include <iosfwd>
 #include <string>
@@ -57,5 +56,3 @@ private:
                            int dim, std::vector<GeoLib::Point*>& points);
 };
 }  // FileIO
-
-#endif /* FEFLOWGEOINTERFACE_H_ */
diff --git a/Applications/FileIO/FEFLOW/FEFLOWMeshInterface.h b/Applications/FileIO/FEFLOW/FEFLOWMeshInterface.h
index 82c21b89252903c7fd03c6a575292ed35de45785..67d20008ff726d0463b81104c10d309349bdb1ff 100644
--- a/Applications/FileIO/FEFLOW/FEFLOWMeshInterface.h
+++ b/Applications/FileIO/FEFLOW/FEFLOWMeshInterface.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef FEFLOWMESHINTERFACE_H_
-#define FEFLOWMESHINTERFACE_H_
+#pragma once
 
 #include <iosfwd>
 #include <string>
@@ -125,5 +124,3 @@ private:
         std::vector<int>& material_ids);
 };
 }  // FileIO
-
-#endif /* FEFLOWMESHINTERFACE_H_ */
diff --git a/Applications/FileIO/GMSInterface.h b/Applications/FileIO/GMSInterface.h
index 30f3a89cd4a5262e5a83e37fcd876858d178e7c1..591ebd845690a17c8c7416a68e0cba49a6237ac3 100644
--- a/Applications/FileIO/GMSInterface.h
+++ b/Applications/FileIO/GMSInterface.h
@@ -15,8 +15,7 @@
  * @author Lars Bilke
  */
 
-#ifndef GMSINTERFACE_H_
-#define GMSINTERFACE_H_
+#pragma once
 
 #include <list>
 #include <string>
@@ -80,5 +79,3 @@ private:
 };
 
 }
-
-#endif /* GMSINTERFACE_H_ */
diff --git a/Applications/FileIO/Gmsh/GMSHAdaptiveMeshDensity.h b/Applications/FileIO/Gmsh/GMSHAdaptiveMeshDensity.h
index 410d4d9417715863fa36a0d11e893e3bbd03ad58..3b3680eff7714da83d16ded14debf6afac51ce94 100644
--- a/Applications/FileIO/Gmsh/GMSHAdaptiveMeshDensity.h
+++ b/Applications/FileIO/Gmsh/GMSHAdaptiveMeshDensity.h
@@ -8,8 +8,7 @@
  *
  */
 
-#ifndef GMSHADAPTIVEMESHDENSITY_H_
-#define GMSHADAPTIVEMESHDENSITY_H_
+#pragma once
 
 #include "GMSHMeshDensityStrategy.h"
 
@@ -55,5 +54,3 @@ private:
 
 }
 } // end namespace FileIO
-
-#endif /* GMSHADAPTIVEMESHDENSITY_H_ */
diff --git a/Applications/FileIO/Gmsh/GMSHFixedMeshDensity.h b/Applications/FileIO/Gmsh/GMSHFixedMeshDensity.h
index d68b23a098108579fc14a1318481ec86991d1741..fb4fb2bea08e18b9245d3ecf3635a4a2688cfcae 100644
--- a/Applications/FileIO/Gmsh/GMSHFixedMeshDensity.h
+++ b/Applications/FileIO/Gmsh/GMSHFixedMeshDensity.h
@@ -8,8 +8,7 @@
  *
  */
 
-#ifndef GMSHFIXEDMESHDENSITY_H_
-#define GMSHFIXEDMESHDENSITY_H_
+#pragma once
 
 #include "GMSHMeshDensityStrategy.h"
 
@@ -33,5 +32,3 @@ private:
 
 }
 } // end namespace FileIO
-
-#endif /* GMSHFIXEDMESHDENSITY_H_ */
diff --git a/Applications/FileIO/Gmsh/GMSHInterface.h b/Applications/FileIO/Gmsh/GMSHInterface.h
index d687a893e1b1d40ab9a8a8179aba3a41997cfd90..ef6a7dc5c59bd747718c4e1dbd9564930edc9c31 100644
--- a/Applications/FileIO/Gmsh/GMSHInterface.h
+++ b/Applications/FileIO/Gmsh/GMSHInterface.h
@@ -8,8 +8,7 @@
  *
  */
 
-#ifndef GMSHINTERFACE_H_
-#define GMSHINTERFACE_H_
+#pragma once
 
 #include <iosfwd>
 
@@ -116,5 +115,3 @@ private:
 };
 } // end namespace GMSH
 } // end namespace FileIO
-
-#endif /* GMSHINTERFACE_H_ */
diff --git a/Applications/FileIO/Gmsh/GMSHLine.h b/Applications/FileIO/Gmsh/GMSHLine.h
index 58b9c36960bad8a68ce335be07927948e8bc0d3e..994e5d861d62f38984469c350bff711a0b904cd2 100644
--- a/Applications/FileIO/Gmsh/GMSHLine.h
+++ b/Applications/FileIO/Gmsh/GMSHLine.h
@@ -8,8 +8,7 @@
  *
  */
 
-#ifndef GMSHLINE_H_
-#define GMSHLINE_H_
+#pragma once
 
 #include <iosfwd>
 
@@ -31,5 +30,3 @@ private:
 
 } // end namespace GMSH
 } // end namespace FileIO
-
-#endif /* GMSHLINE_H_ */
diff --git a/Applications/FileIO/Gmsh/GMSHLineLoop.h b/Applications/FileIO/Gmsh/GMSHLineLoop.h
index c5a0d064b72d75b2ce0dae97c5a0155df83d5628..1c156d4268ae33f16c67234a176bd110cad1fd37 100644
--- a/Applications/FileIO/Gmsh/GMSHLineLoop.h
+++ b/Applications/FileIO/Gmsh/GMSHLineLoop.h
@@ -8,8 +8,7 @@
  *
  */
 
-#ifndef GMSHLINELOOP_H_
-#define GMSHLINELOOP_H_
+#pragma once
 
 #include <vector>
 #include <iosfwd>
@@ -37,5 +36,3 @@ private:
 
 }  // end namespace GMSH
 }  // end namespace FileIO
-
-#endif /* GMSHLINELOOP_H_ */
diff --git a/Applications/FileIO/Gmsh/GMSHMeshDensityStrategy.h b/Applications/FileIO/Gmsh/GMSHMeshDensityStrategy.h
index 682e1de84a872cd7a4ccef1ae9f0051c44d6a05a..3b14475dabf9492eb19adacb5dcfa45e319af86d 100644
--- a/Applications/FileIO/Gmsh/GMSHMeshDensityStrategy.h
+++ b/Applications/FileIO/Gmsh/GMSHMeshDensityStrategy.h
@@ -8,8 +8,7 @@
  *
  */
 
-#ifndef GMSHMESHDENSITYSTRATEGY_H_
-#define GMSHMESHDENSITYSTRATEGY_H_
+#pragma once
 
 #include <vector>
 
@@ -37,5 +36,3 @@ public:
 
 }  // end namespace GMSH
 }  // end namespace FileIO
-
-#endif /* GMSHMESHDENSITYSTRATEGY_H_ */
diff --git a/Applications/FileIO/Gmsh/GMSHPoint.h b/Applications/FileIO/Gmsh/GMSHPoint.h
index 4441b49f9c5637c55e59630654e988f2e903fb35..f1a4f11c1d915ea9ab6bcdf04b589e334463b208 100644
--- a/Applications/FileIO/Gmsh/GMSHPoint.h
+++ b/Applications/FileIO/Gmsh/GMSHPoint.h
@@ -8,8 +8,7 @@
  *
  */
 
-#ifndef GMSHPOINT_H_
-#define GMSHPOINT_H_
+#pragma once
 
 // GeoLib
 #include "GeoLib/Point.h"
@@ -32,5 +31,3 @@ std::ostream& operator<< (std::ostream &os, GMSHPoint const& p);
 
 }  // end namespace GMSH
 }  // end namespace FileIO
-
-#endif /* GMSHPOINT_H_ */
diff --git a/Applications/FileIO/Gmsh/GMSHPolygonTree.h b/Applications/FileIO/Gmsh/GMSHPolygonTree.h
index 2094bdd31f5e823828c129e16364bce1356349fa..0ed605482b77af64948668c10a01329eb1daf743 100644
--- a/Applications/FileIO/Gmsh/GMSHPolygonTree.h
+++ b/Applications/FileIO/Gmsh/GMSHPolygonTree.h
@@ -8,8 +8,7 @@
  *
  */
 
-#ifndef GMSHPOLYGONTREE_H_
-#define GMSHPOLYGONTREE_H_
+#pragma once
 
 #include <vector>
 #include <string>
@@ -102,5 +101,3 @@ private:
 
 }  // end namespace GMSH
 }  // end namespace FileIO
-
-#endif /* GMSHPOLYGONTREE_H_ */
diff --git a/Applications/FileIO/PetrelInterface.h b/Applications/FileIO/PetrelInterface.h
index 84618b8b96b696e35a722f7fec7deef146518844..6c071df9c0b754b7f00fce214464b63caceb91c7 100644
--- a/Applications/FileIO/PetrelInterface.h
+++ b/Applications/FileIO/PetrelInterface.h
@@ -15,8 +15,7 @@
  * @author Thomas Fischer
  */
 
-#ifndef PETRELIO_H_
-#define PETRELIO_H_
+#pragma once
 
 #include <iosfwd>
 #include <list>
@@ -51,5 +50,3 @@ private:
     static const std::size_t MAX_COLS_PER_ROW = 256;
 };
 } // end namespace FileIO
-
-#endif /* PETRELIO_H_ */
diff --git a/Applications/FileIO/SHPInterface.h b/Applications/FileIO/SHPInterface.h
index 14188b49ac877f3ef778c1dc74e1aa894f4d7117..4c484cfae0dd92dd5fbcdde33b095bcef1c90f09 100644
--- a/Applications/FileIO/SHPInterface.h
+++ b/Applications/FileIO/SHPInterface.h
@@ -15,8 +15,7 @@
  * @author Karsten Rink
  */
 
-#ifndef SHPINTERFACE_H
-#define SHPINTERFACE_H
+#pragma once
 
 #include <string>
 #include <vector>
@@ -85,5 +84,3 @@ private:
 };
 
 }
-
-#endif //SHPINTERFACE_H
diff --git a/Applications/FileIO/SWMM/SWMMInterface.h b/Applications/FileIO/SWMM/SWMMInterface.h
index 8b050484ce3aa7b4f93caaf147fd601827097083..da001e9d810d6bd123701f4736748e6dfbd00976 100644
--- a/Applications/FileIO/SWMM/SWMMInterface.h
+++ b/Applications/FileIO/SWMM/SWMMInterface.h
@@ -5,8 +5,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef SWMMINTERFACE_H_
-#define SWMMINTERFACE_H_
+#pragma once
 
 #include <map>
 #include <memory>
@@ -214,5 +213,3 @@ private:
 };
 
 } // namespace FileIO
-
-#endif // SWMMINTERFACE_H_
diff --git a/Applications/FileIO/TetGenInterface.h b/Applications/FileIO/TetGenInterface.h
index dd665b7fcae7c054c4dc0cf20e12af912f51b348..05896a60b727123f3a944fd5eea1b3099ec5587b 100644
--- a/Applications/FileIO/TetGenInterface.h
+++ b/Applications/FileIO/TetGenInterface.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef TETGENINTERFACE_H_
-#define TETGENINTERFACE_H_
+#pragma once
 
 #include <vector>
 
@@ -216,5 +215,3 @@ private:
     bool _boundary_markers;
 };
 }
-
-#endif /* TETGENINTERFACE_H_ */
diff --git a/Applications/FileIO/XmlIO/Qt/XmlGspInterface.h b/Applications/FileIO/XmlIO/Qt/XmlGspInterface.h
index a3fbb4406952823104f10c40f17a2b7104e3066c..720a1ad53a1c86631e0ac8fa2adb19d500e2f867 100644
--- a/Applications/FileIO/XmlIO/Qt/XmlGspInterface.h
+++ b/Applications/FileIO/XmlIO/Qt/XmlGspInterface.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef XMLGSPINTERFACE_H
-#define XMLGSPINTERFACE_H
+#pragma once
 
 #include <vector>
 #include <string>
@@ -56,5 +55,3 @@ private:
 };
 
 } // end namespace FileIO
-
-#endif // XMLGSPINTERFACE_H
diff --git a/Applications/FileIO/XmlIO/Qt/XmlLutReader.h b/Applications/FileIO/XmlIO/Qt/XmlLutReader.h
index 5cd3f7db7ea6a5065acd905174d6eb2d3001f1c4..2b52c964dd91ea2f60585e342b9f3a7645f31dca 100644
--- a/Applications/FileIO/XmlIO/Qt/XmlLutReader.h
+++ b/Applications/FileIO/XmlIO/Qt/XmlLutReader.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef XMLLUTREADER_H
-#define XMLLUTREADER_H
+#pragma once
 
 #include <QFile>
 #include <QtXml/QDomDocument>
@@ -101,5 +100,3 @@ public:
 };
 
  }
-
-#endif // XMLLUTREADER_H
diff --git a/Applications/FileIO/XmlIO/Qt/XmlNumInterface.h b/Applications/FileIO/XmlIO/Qt/XmlNumInterface.h
index 25221d1b730e2e1b0718cf859dfdb239d861951b..e4a10027469fdad343c911abed83de052bf8b97e 100644
--- a/Applications/FileIO/XmlIO/Qt/XmlNumInterface.h
+++ b/Applications/FileIO/XmlIO/Qt/XmlNumInterface.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef XMLNUMINTERFACE_H
-#define XMLNUMINTERFACE_H
+#pragma once
 
 #include "BaseLib/IO/XmlIO/XMLInterface.h"
 #include "BaseLib/IO/XmlIO/Qt/XMLQtInterface.h"
@@ -41,5 +40,3 @@ protected:
 };
 
 }
-
-#endif // XMLNUMINTERFACE_H
diff --git a/Applications/Utils/ModelPreparation/PartitionMesh/NodeWiseMeshPartitioner.h b/Applications/Utils/ModelPreparation/PartitionMesh/NodeWiseMeshPartitioner.h
index 8666f0da852452bf4e90795c98126644396b8c64..c1505252263b5912773eafccc2afc8a78fcbe734 100644
--- a/Applications/Utils/ModelPreparation/PartitionMesh/NodeWiseMeshPartitioner.h
+++ b/Applications/Utils/ModelPreparation/PartitionMesh/NodeWiseMeshPartitioner.h
@@ -12,8 +12,7 @@
 
 */
 
-#ifndef NODE_WISE_MESH_PARTITIONER_H_
-#define NODE_WISE_MESH_PARTITIONER_H_
+#pragma once
 
 #include <memory>
 #include <tuple>
@@ -192,5 +191,3 @@ private:
 };
 
 }  // namespace MeshLib
-
-#endif  // NODE_WISE_MESH_PARTITIONER_H_
diff --git a/Applications/Utils/OGSFileConverter/FileListDialog.h b/Applications/Utils/OGSFileConverter/FileListDialog.h
index a574dafc41093fbb3376b96e74007fcbec36b8d1..cfe7b07925073b353c2935d34391d5f1a35eb942 100644
--- a/Applications/Utils/OGSFileConverter/FileListDialog.h
+++ b/Applications/Utils/OGSFileConverter/FileListDialog.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef FILELISTDIALOG_H
-#define FILELISTDIALOG_H
+#pragma once
 
 #include "ui_FileList.h"
 #include <QDialog>
@@ -68,5 +67,3 @@ private slots:
     void reject();
 
 };
-
-#endif //FILELISTDIALOG_H
diff --git a/Applications/Utils/OGSFileConverter/OGSFileConverter.h b/Applications/Utils/OGSFileConverter/OGSFileConverter.h
index 92d24cc4d40ae19f55a15b3bb172db955bf38a4c..99f6ed0227132266f047d9fe71e38b75558c8de5 100644
--- a/Applications/Utils/OGSFileConverter/OGSFileConverter.h
+++ b/Applications/Utils/OGSFileConverter/OGSFileConverter.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef OGSFILECONVERTER_H
-#define OGSFILECONVERTER_H
+#pragma once
 
 #include "ui_OGSFileConverter.h"
 #include <QDialog>
@@ -48,5 +47,3 @@ private slots:
     void on_msh2vtuButton_pressed() const;
     void on_closeDialogButton_pressed();
 };
-
-#endif //OGSFILECONVERTER_H
diff --git a/BaseLib/BuildInfo.h b/BaseLib/BuildInfo.h
index 95e412b1170ee497e4be46ab5e78f85cca27d6a0..cc888557d63daa0055fa89ab0f5a6eb346367b89 100644
--- a/BaseLib/BuildInfo.h
+++ b/BaseLib/BuildInfo.h
@@ -9,8 +9,7 @@
  *
  */
 
-#ifndef BASE_LIB_BUILD_INFO_H_
-#define BASE_LIB_BUILD_INFO_H_
+#pragma once
 
 #include <string>
 
@@ -40,5 +39,3 @@ namespace BuildInfo
     extern const std::string tests_tmp_path;
 }
 }
-
-#endif  // BASE_LIB_BUILD_INFO_H_
diff --git a/BaseLib/CPUTime.h b/BaseLib/CPUTime.h
index cfaa2c8f80dd689458f5d4a86d952701cfce7b7e..6905c4508c621ec82a230f60705c79bcc96379c3 100644
--- a/BaseLib/CPUTime.h
+++ b/BaseLib/CPUTime.h
@@ -13,8 +13,7 @@
  *
  */
 
-#ifndef CPUTIME_H
-#define CPUTIME_H
+#pragma once
 
 #include <ctime>
 
@@ -41,6 +40,3 @@ class CPUTime
 };
 
 } // end namespace BaseLib
-
-#endif
-
diff --git a/BaseLib/CodingTools.h b/BaseLib/CodingTools.h
index aa3f3c76499f82fe2e8d854469fef9d5af0cbc87..ddc930a1a12a83e8ea11a947c1158e84576c26a7 100644
--- a/BaseLib/CodingTools.h
+++ b/BaseLib/CodingTools.h
@@ -12,11 +12,8 @@
  *
  */
 
-#ifndef CODINGTOOLS_H
-#define CODINGTOOLS_H
+#pragma once
 
 #define DISALLOW_COPY_AND_ASSIGN(TypeName) \
     TypeName(const TypeName&);   \
     TypeName &operator=(const TypeName&)
-
-#endif
diff --git a/BaseLib/ConfigTree.h b/BaseLib/ConfigTree.h
index 5ca4a06206877d1a4d85fc2218f27aea564c9744..8f8bcc20fb045191a5e38cd6d014cf8734c0b05d 100644
--- a/BaseLib/ConfigTree.h
+++ b/BaseLib/ConfigTree.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef BASELIB_CONFIGTREE_H_
-#define BASELIB_CONFIGTREE_H_
+#pragma once
 
 #include <typeindex>
 #include <map>
@@ -645,7 +644,3 @@ private:
 }
 
 #include "ConfigTree-impl.h"
-
-
-#endif // BASELIB_CONFIGTREE_H_
-
diff --git a/BaseLib/ConfigTreeUtil.h b/BaseLib/ConfigTreeUtil.h
index e783fc2ec8b4bfc9e2db074e304a46fbb0881249..17d80e7760b7378eb48442257c3db28e98867792 100644
--- a/BaseLib/ConfigTreeUtil.h
+++ b/BaseLib/ConfigTreeUtil.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef BASELIB_CONFIGTREEUTIL
-#define BASELIB_CONFIGTREEUTIL
+#pragma once
 
 #include "ConfigTree.h"
 
@@ -89,5 +88,3 @@ makeConfigTree(std::string const& filepath, bool const be_ruthless,
                std::string const& toplevel_tag);
 
 }
-
-#endif
diff --git a/BaseLib/Counter.h b/BaseLib/Counter.h
index 355ee83843398c11537d7a7ceb92d59df4884833..6352428137513b5356b641c240deb95ef3b7299e 100644
--- a/BaseLib/Counter.h
+++ b/BaseLib/Counter.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef BASELIB_GLOBALCOUNTER_H
-#define BASELIB_GLOBALCOUNTER_H
+#pragma once
 
 #include <cstddef>
 
@@ -27,5 +26,3 @@ struct Counter
 template <typename X> std::size_t Counter<X>::_counter_value(0);
 
 } // end namespace BaseLib
-
-#endif  // BASELIB_GLOBALCOUNTER_H
diff --git a/BaseLib/DateTools.h b/BaseLib/DateTools.h
index d9cf93510ff383466939098d74be0791775dac31..783b60d611aada0373a75bb43830d42c98fe1d24 100644
--- a/BaseLib/DateTools.h
+++ b/BaseLib/DateTools.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef DATETOOLS_H
-#define DATETOOLS_H
+#pragma once
 
 #include <chrono>
 #include <string>
@@ -67,5 +66,3 @@ std::string formatDate(
     std::chrono::time_point<std::chrono::system_clock> const& time);
 
 } // namespace BaseLib
-
-#endif //DATETOOLS_H
diff --git a/BaseLib/DebugTools.h b/BaseLib/DebugTools.h
index f2695c1648cc58058aa37efaef9e9580f09f4b1d..1d20d528af3406d4514ea86626d5d9864d3fae81 100644
--- a/BaseLib/DebugTools.h
+++ b/BaseLib/DebugTools.h
@@ -11,8 +11,7 @@
  *
  */
 
-#ifndef DEBUGTOOLS_H
-#define DEBUGTOOLS_H
+#pragma once
 
 #include <ostream>
 #include <algorithm>
@@ -24,6 +23,3 @@ std::ostream &operator <<(std::ostream &os, const std::vector<T> &v) {
     os << "\n";
     return os;
 }
-
-#endif //DEBUGTOOLS_H
-
diff --git a/BaseLib/Error.h b/BaseLib/Error.h
index c418204d4cd4722a013b20182ca46bd4d73dd7cb..517c051bca2218826b779669fe4f7c7fc67403af 100644
--- a/BaseLib/Error.h
+++ b/BaseLib/Error.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef BASELIB_ERROR_H
-#define BASELIB_ERROR_H
+#pragma once
 
 #ifdef OGS_FATAL_ABORT
 
@@ -36,5 +35,3 @@
     throw std::runtime_error(BaseLib::format(fmt, ##__VA_ARGS__) + OGS_LOCATION);
 
 #endif // OGS_FATAL_ABORT
-
-#endif //BASELIB_ERROR_H
diff --git a/BaseLib/FileFinder.h b/BaseLib/FileFinder.h
index f9a8fee7d180cfab6afd1eeca65e0c6951c31685..02c412aa2d717095a86652f74bb1e343c574c431 100644
--- a/BaseLib/FileFinder.h
+++ b/BaseLib/FileFinder.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef FILEFINDER_H
-#define FILEFINDER_H
+#pragma once
 
 #include <initializer_list>
 #include <string>
@@ -57,5 +56,3 @@ private:
     std::vector<std::string> _directories;
 };
 } // end namespace BaseLib
-
-#endif // FILEFINDER_H
diff --git a/BaseLib/FileTools.h b/BaseLib/FileTools.h
index 920864b2b5b3ba1b04b43aff31d398a60deb992f..c4cb8e6f77eb223afdf1af98a3e5e190511e3aaf 100644
--- a/BaseLib/FileTools.h
+++ b/BaseLib/FileTools.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef FILETOOLS_H
-#define FILETOOLS_H
+#pragma once
 
 #include <fstream>
 #include <string>
@@ -163,5 +162,3 @@ std::string appendPathSeparator(std::string const& path);
 std::string joinPaths(std::string const& pathA, std::string const& pathB);
 
 } // end namespace BaseLib
-
-#endif // FILETOOLS_H
diff --git a/BaseLib/Functional.h b/BaseLib/Functional.h
index 55b4b453a51198f28fcd754dafc886930cf4809d..000a2c9e5f85a0ca32f2874fa932ce4f55402be4 100644
--- a/BaseLib/Functional.h
+++ b/BaseLib/Functional.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef BASELIB_FUNCTIONAL_H
-#define BASELIB_FUNCTIONAL_H
+#pragma once
 
 #include <functional>
 #include "BaseLib/TMPUtil.h"
@@ -212,5 +211,3 @@ typename detail::FunctionTraits<Object>::FunctionType easyBind(Object&& obj)
 }
 
 }  // namespace BaseLib
-
-#endif  // BASELIB_FUNCTIONAL_H
diff --git a/BaseLib/Histogram.h b/BaseLib/Histogram.h
index 88218b7b8356b726d49663ba76df9f3c550104fd..5c7155a896feb10ab68156f33d54c93bbb7d333a 100644
--- a/BaseLib/Histogram.h
+++ b/BaseLib/Histogram.h
@@ -10,8 +10,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef BASELIB_HISTOGRAM_H
-#define BASELIB_HISTOGRAM_H
+#pragma once
 
 #include <algorithm>
 #include <cmath>
@@ -196,5 +195,3 @@ operator<<(std::ostream& os, const Histogram<T>& h)
     return os << std::endl;
 }
 }   // namespace BaseLib
-
-#endif  // BASELIB_HISTOGRAM_H
diff --git a/BaseLib/IO/Writer.h b/BaseLib/IO/Writer.h
index a1c7f3db7437d2c58ce6206fab7d3ea98740088d..0dabb332349bf43675a4a32ee6a89cf634aa4013 100644
--- a/BaseLib/IO/Writer.h
+++ b/BaseLib/IO/Writer.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef WRITER_H
-#define WRITER_H
+#pragma once
 
 #include <string>
 #include <sstream>
@@ -62,5 +61,3 @@ private:
 
 } // namespace IO
 } // namespace BaseLib
-
-#endif // WRITER_H
diff --git a/BaseLib/IO/XmlIO/Qt/XMLQtInterface.h b/BaseLib/IO/XmlIO/Qt/XMLQtInterface.h
index 2e85768f9bacd5de56e48ee9ed6087533f80e5bd..e290c0643397e90bdcd39cc1cf7a19ef7f264645 100644
--- a/BaseLib/IO/XmlIO/Qt/XMLQtInterface.h
+++ b/BaseLib/IO/XmlIO/Qt/XMLQtInterface.h
@@ -10,8 +10,7 @@
  *              See accompanying file LICENSE.txt or
  *              http://www.opengeosys.org/LICENSE.txt
  */
-#ifndef XMLQTINTERFACE_H_
-#define XMLQTINTERFACE_H_
+#pragma once
 
 #include <string>
 
@@ -64,5 +63,3 @@ protected:
 
 } // end namespace IO
 } // end namespace BaseLib
-
-#endif /* XMLQTINTERFACE_H_ */
diff --git a/BaseLib/IO/XmlIO/XMLInterface.h b/BaseLib/IO/XmlIO/XMLInterface.h
index 5f8a4d499d75e681c2a0bbe2b1329ac0b6fc5b81..d8c8cbb98706109a616d7768c78b7e011c3eaa91 100644
--- a/BaseLib/IO/XmlIO/XMLInterface.h
+++ b/BaseLib/IO/XmlIO/XMLInterface.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef XMLINTERFACE_H
-#define XMLINTERFACE_H
+#pragma once
 
 #include <string>
 
@@ -41,5 +40,3 @@ protected:
 
 }
 }
-
-#endif // XMLINTERFACE_H
diff --git a/BaseLib/LogogCustomCout.h b/BaseLib/LogogCustomCout.h
index 19903bb02877d4ac7d15967ec05462a1996943f8..750a4e2513d5f0bc7c8d9cf709fcf312289f8957 100644
--- a/BaseLib/LogogCustomCout.h
+++ b/BaseLib/LogogCustomCout.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef LOGOGCUSTOMCOUT_H_
-#define LOGOGCUSTOMCOUT_H_
+#pragma once
 
 #include <ostream>
 
@@ -66,6 +65,4 @@ private:
 #endif
 };
 
-#endif // LOGOGCUSTOMCOUT_H_
-
 } // namespace BaseLib
diff --git a/BaseLib/LogogSimpleFormatter.h b/BaseLib/LogogSimpleFormatter.h
index c805a1c4f5e47ea0be61ed676be73433255cc3fd..eeaab28468e7aaa5018c7adc795b5f7c739fd030 100644
--- a/BaseLib/LogogSimpleFormatter.h
+++ b/BaseLib/LogogSimpleFormatter.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef LOGOGSIMPLEFORMATTER_H
-#define LOGOGSIMPLEFORMATTER_H
+#pragma once
 
 #include <logog/include/logog.hpp>
 
@@ -34,5 +33,3 @@ class LogogSimpleFormatter : public logog::FormatterMSVC
 };
 
 }  // namespace BaseLib
-
-#endif  // LOGOGSIMPLEFORMATTER_H
diff --git a/BaseLib/MemWatch.h b/BaseLib/MemWatch.h
index 3afd3fcd4710ffbcb3e797c6fc95beee4d2ae212..cfbb92d8818eb0a2501f3118192f9a52aead1af0 100644
--- a/BaseLib/MemWatch.h
+++ b/BaseLib/MemWatch.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef MEMWATCH_H_
-#define MEMWATCH_H_
+#pragma once
 
 namespace BaseLib {
 
@@ -34,5 +33,3 @@ private:
 };
 
 }
-
-#endif /* MEMWATCH_H_ */
diff --git a/BaseLib/RunTime.h b/BaseLib/RunTime.h
index 91ead6496cc3f67a6b9f3f9e238865f175b0d077..197ec678baf43a6067e09d5ae7811ee27af59ea2 100644
--- a/BaseLib/RunTime.h
+++ b/BaseLib/RunTime.h
@@ -13,8 +13,7 @@
  *
  */
 
-#ifndef RUNTIME_H
-#define RUNTIME_H
+#pragma once
 
 #if defined(USE_MPI)
 #include <mpi.h>
@@ -70,5 +69,3 @@ class RunTime
 };
 
 } // end namespace BaseLib
-
-#endif
diff --git a/BaseLib/StringTools.h b/BaseLib/StringTools.h
index 4138e36053a124301766e3dbd68dab4617bfca09..7702d794a5f9e5b363050a90ef38fd3e939d866b 100644
--- a/BaseLib/StringTools.h
+++ b/BaseLib/StringTools.h
@@ -12,9 +12,7 @@
  *
  */
 
-#ifndef STRINGTOOLS_H
-#define STRINGTOOLS_H
-
+#pragma once
 
 #include <string>
 #include <list>
@@ -96,5 +94,3 @@ std::string format(const char* format_string, ... );
 #ifdef MSVC
 void correctScientificNotation(std::string filename, std::size_t precision = 0);
 #endif
-
-#endif //STRINGTOOLS_H
diff --git a/BaseLib/Subdivision.h b/BaseLib/Subdivision.h
index 370b308a93cca40f44830bae0e8506a27240e723..dbfa4c576e01c7ad438374eb0ca7d4014fa17b70 100644
--- a/BaseLib/Subdivision.h
+++ b/BaseLib/Subdivision.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef SUBDIVISION_H_
-#define SUBDIVISION_H_
+#pragma once
 
 #include <cmath>
 
@@ -108,5 +107,3 @@ private:
 };
 
 } // BaseLib
-
-#endif /* SUBDIVISION_H_ */
diff --git a/BaseLib/TCLAPCustomOutput.h b/BaseLib/TCLAPCustomOutput.h
index 20b3daa186f65fdbd3164ba5f680a00f40489fde..dea0f3c0070f6c04f99e18dd2121cc114b975a1f 100644
--- a/BaseLib/TCLAPCustomOutput.h
+++ b/BaseLib/TCLAPCustomOutput.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/LICENSE.txt
  */
 
-#ifndef TCLAPCUSTOMOUTPUT_H_
-#define TCLAPCUSTOMOUTPUT_H_
+#pragma once
 
 #include <string>
 #include <vector>
@@ -179,6 +178,3 @@ TCLAPCustomOutput::_longUsage( TCLAP::CmdLineInterface& _cmd,
 }
 
 } //namespace BaseLib
-
-#endif /* TCLAPCUSTOMOUTPUT_H_ */
-
diff --git a/BaseLib/TMPUtil.h b/BaseLib/TMPUtil.h
index 5297bea5ed9770bb71c6e6231683bb498240048e..1b0d8fdb0a32161fdc62506f608564252c497259 100644
--- a/BaseLib/TMPUtil.h
+++ b/BaseLib/TMPUtil.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef BASELIB_TMPUTIL_H
-#define BASELIB_TMPUTIL_H
+#pragma once
 
 namespace BaseLib
 {
@@ -42,5 +41,3 @@ struct GenerateIntegerSequence<0, S...> {
  */
 
 }  // namespace BaseLib
-
-#endif  // BASELIB_TMPUTIL_H
diff --git a/BaseLib/TemplateLogogFormatterSuppressedGCC.h b/BaseLib/TemplateLogogFormatterSuppressedGCC.h
index 7e4d736cb570e815aff8e58305eef4138e059c2f..52730d867da576c7d8522588675aace9216f6985 100644
--- a/BaseLib/TemplateLogogFormatterSuppressedGCC.h
+++ b/BaseLib/TemplateLogogFormatterSuppressedGCC.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef TEMPLATELOGOGFORMATTERSUPPRESSEDGCC_H_
-#define TEMPLATELOGOGFORMATTERSUPPRESSEDGCC_H_
+#pragma once
 
 #include <string>
 
@@ -56,5 +55,3 @@ private:
 } // namespace BaseLib
 
 #include "TemplateLogogFormatterSuppressedGCC-impl.h"
-
-#endif // TEMPLATELOGOGFORMATTERSUPPRESSEDGCC_H_
diff --git a/BaseLib/excludeObjectCopy.h b/BaseLib/excludeObjectCopy.h
index d8dc41fce759a1e279b23afd6badaa9aab151982..65fed57969a31eb0410de99de41ccb6562f9dcd5 100644
--- a/BaseLib/excludeObjectCopy.h
+++ b/BaseLib/excludeObjectCopy.h
@@ -8,8 +8,7 @@
  *
  */
 
-#ifndef EXCLUDEOBJECTCOPIER_H_
-#define EXCLUDEOBJECTCOPIER_H_
+#pragma once
 
 #include <vector>
 #include <algorithm>
@@ -61,6 +60,3 @@ void excludeObjectCopy(std::vector<T> const& src_vec,
 
 
 } // end namespace BaseLib
-
-#endif
-
diff --git a/BaseLib/makeVectorUnique.h b/BaseLib/makeVectorUnique.h
index 7efbb1251a0d362e903aa9d33365289dfc49094b..cc6bf7ae27a8b5ca34e2e8886082fe2d77f1897e 100644
--- a/BaseLib/makeVectorUnique.h
+++ b/BaseLib/makeVectorUnique.h
@@ -8,8 +8,7 @@
  *
  */
 
-#ifndef MAKEVECTORUNIQUE_H
-#define MAKEVECTORUNIQUE_H
+#pragma once
 
 #include <algorithm>
 #include <vector>
@@ -38,4 +37,3 @@ void makeVectorUnique(std::vector<T>& v, Compare comp)
 }
 
 } // end namespace BaseLib
-#endif
diff --git a/BaseLib/quicksort.h b/BaseLib/quicksort.h
index 02960b98c3fed9029780aa332316929b87cebdf6..a5f0e9905ceca530f2dd1a72c6c53ec9b5c67cde 100644
--- a/BaseLib/quicksort.h
+++ b/BaseLib/quicksort.h
@@ -9,8 +9,7 @@
  *
  */
 
-#ifndef QUICKSORT_H_
-#define QUICKSORT_H_
+#pragma once
 
 #include <algorithm>
 #include <cassert>
@@ -95,5 +94,3 @@ void quicksort(std::vector<T1*>& array, std::size_t beg, std::size_t end, std::v
 }
 
 } // end namespace BaseLib
-
-#endif /* QUICKSORT_H_ */
diff --git a/BaseLib/reorderVector.h b/BaseLib/reorderVector.h
index e6dfbac62bbe69c2fedb1c0f4c3ba6394ab4f860..230cf6ee1076c28ba932f9449b9ba557abd2f970 100644
--- a/BaseLib/reorderVector.h
+++ b/BaseLib/reorderVector.h
@@ -11,8 +11,7 @@
  * Created on October 13, 2016, 5:37 PM
  */
 
-#ifndef OGS_BASELIB_REORDERVECTOR_H
-#define OGS_BASELIB_REORDERVECTOR_H
+#pragma once
 
 namespace BaseLib
 {
@@ -35,5 +34,3 @@ void reorderVector(std::vector<ValueType>& v,
 }
 
 } // end of namespace
-#endif /* OGS_BASELIB_REORDERVECTOR_H */
-
diff --git a/BaseLib/uniqueInsert.h b/BaseLib/uniqueInsert.h
index e7b4c2693d08345dc52ae51aecbfc819b9e60f72..25aa7e2847932863fc6c7087e69fc826ea42b530 100644
--- a/BaseLib/uniqueInsert.h
+++ b/BaseLib/uniqueInsert.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef UNIQUELISTINSERT_H_
-#define UNIQUELISTINSERT_H_
+#pragma once
 
 #include <algorithm>
 
@@ -99,5 +98,3 @@ getOrError(
 }
 
 } // end namespace BaseLib
-
-#endif /* UNIQUELISTINSERT_H_ */
diff --git a/GeoLib/AABB.h b/GeoLib/AABB.h
index 617c838a49e6215ea9b53f538e6c5505db45d616..4abf643ff398e427528f6ca821e40abbbd3ec1c9 100644
--- a/GeoLib/AABB.h
+++ b/GeoLib/AABB.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef AABB_H_
-#define AABB_H_
+#pragma once
 
 #include <bitset>
 #include <cassert>
@@ -246,5 +245,3 @@ private:
     }
 };
 } // end namespace
-
-#endif /* AABB_H_ */
diff --git a/GeoLib/AnalyticalGeometry.h b/GeoLib/AnalyticalGeometry.h
index 99d8ac0e0f39b9cd6a4e1526910aa78247ad09ec..6a2d544a069e3872641401f561bccec26d30492a 100644
--- a/GeoLib/AnalyticalGeometry.h
+++ b/GeoLib/AnalyticalGeometry.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef ANALYTICAL_GEOMETRY_H_
-#define ANALYTICAL_GEOMETRY_H_
+#pragma once
 
 #include <memory>
 
@@ -260,5 +259,3 @@ void sortSegments(MathLib::Point3d const& seg_beg_pnt,
 } // end namespace GeoLib
 
 #include "AnalyticalGeometry-impl.h"
-
-#endif /* ANALYTICAL_GEOMETRY_H_ */
diff --git a/GeoLib/ClosestPair.h b/GeoLib/ClosestPair.h
index a7ea954ab48e7a2f3d00d9a3048e02b5690d01f9..33c4f4b799b897e1f472011a27e3aa200d0c4006 100644
--- a/GeoLib/ClosestPair.h
+++ b/GeoLib/ClosestPair.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef CLOSESTPAIR_H_
-#define CLOSESTPAIR_H_
+#pragma once
 
 // STL
 #include <vector>
@@ -37,5 +36,3 @@ protected:
 };
 
 } // end namespace GeoLib
-
-#endif /* CLOSESTPAIR_H_ */
diff --git a/GeoLib/DuplicateGeometry.h b/GeoLib/DuplicateGeometry.h
index d501028e8352328cd3a9fa4a6243ca3b7c8c5360..820f09a3df5fe9a554875ca5665a2324b1540eff 100644
--- a/GeoLib/DuplicateGeometry.h
+++ b/GeoLib/DuplicateGeometry.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef DUPLICATEGEOMETRY_H_
-#define DUPLICATEGEOMETRY_H_
+#pragma once
 
 #include <memory>
 #include <string>
@@ -65,5 +64,3 @@ private:
 }; // class
 
 } // namespace
-
-#endif /* DUPLICATEGEOMETRY_H_ */
diff --git a/GeoLib/EarClippingTriangulation.h b/GeoLib/EarClippingTriangulation.h
index ad097ad156b2d82a3930042c0eaa3fe4f447e4d7..839887766bd449edab857e77f1792e1ba286b216 100644
--- a/GeoLib/EarClippingTriangulation.h
+++ b/GeoLib/EarClippingTriangulation.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef EARCLIPPINGTRIANGULATION_H_
-#define EARCLIPPINGTRIANGULATION_H_
+#pragma once
 
 #include <list>
 #include <vector>
@@ -62,5 +61,3 @@ private:
     GeoLib::Orientation _original_orient;
 };
 } // end namespace GeoLib
-
-#endif /* EARCLIPPINGTRIANGULATION_H_ */
diff --git a/GeoLib/GEOObjects.h b/GeoLib/GEOObjects.h
index 5bec7f7398acfac78d781e951d6f35ab7530e919..911ec685c7264e2042aff134706cbb7322bcb93b 100644
--- a/GeoLib/GEOObjects.h
+++ b/GeoLib/GEOObjects.h
@@ -11,8 +11,7 @@
  *
  */
 
-#ifndef GEOOBJECTS_H_
-#define GEOOBJECTS_H_
+#pragma once
 
 #include <map>
 #include <functional>
@@ -352,5 +351,3 @@ private:
             std::string & merged_geo_name, std::vector<std::size_t> const& pnt_offsets);
 };
 } // end namespace
-
-#endif /* GEOOBJECTS_H_ */
diff --git a/GeoLib/GeoObject.h b/GeoLib/GeoObject.h
index 21952b4717c640173001469bb5302d4530531401..0fd6caac36b2327d734bfc19e0bf922bd826c7e4 100644
--- a/GeoLib/GeoObject.h
+++ b/GeoLib/GeoObject.h
@@ -13,8 +13,7 @@
  *
  */
 
-#ifndef GEOOBJECT_H_
-#define GEOOBJECT_H_
+#pragma once
 
 #include "GeoType.h"
 
@@ -31,5 +30,3 @@ public:
     virtual GEOTYPE getGeoType() const = 0;
 };
 } // end namespace GeoLib
-
-#endif /* GEOOBJECT_H_ */
diff --git a/GeoLib/GeoType.h b/GeoLib/GeoType.h
index 8a61ff9ab47b19b4682a3dd177b8237f21d4e080..0051fc33956f6714d9c0e854fd56883a3f57bddd 100644
--- a/GeoLib/GeoType.h
+++ b/GeoLib/GeoType.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef GEOTYPE_H_
-#define GEOTYPE_H_
+#pragma once
 
 #include <string>
 
@@ -32,5 +31,3 @@ enum class GEOTYPE {
 std::string convertGeoTypeToString (GEOTYPE geo_type);
 
 } // end namespace GeoLib
-
-#endif /* GEOTYPE_H_ */
diff --git a/GeoLib/Grid.h b/GeoLib/Grid.h
index 43f8c6f5d9d520eaf1971eff1b0fedf5c1988a8d..fba64e6089b9bb4039f8b6aecc5ab6f155e00501 100644
--- a/GeoLib/Grid.h
+++ b/GeoLib/Grid.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef GRID_H_
-#define GRID_H_
+#pragma once
 
 #include <bitset>
 #include <vector>
@@ -603,5 +602,3 @@ Grid<POINT>::getPointsInEpsilonEnvironment(P const& pnt, double eps) const
 }
 
 } // end namespace GeoLib
-
-#endif /* MESHGRID_H_ */
diff --git a/GeoLib/IO/Legacy/OGSIOVer4.h b/GeoLib/IO/Legacy/OGSIOVer4.h
index 2a369aea39ac29fb1b5e2f41f1d95e0b43c10278..8e1f9ab992ba7434d9ab9284ec70bce149152df8 100644
--- a/GeoLib/IO/Legacy/OGSIOVer4.h
+++ b/GeoLib/IO/Legacy/OGSIOVer4.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef OGSIOVER4_H_
-#define OGSIOVER4_H_
+#pragma once
 
 #include <string>
 #include <vector>
@@ -45,5 +44,3 @@ void writeAllDataToGLIFileV4 (const std::string& fname, const GeoLib::GEOObjects
 }
 } // end namespace IO
 } // end namespace GeoLib
-
-#endif /* OGSIOVER4_H_ */
diff --git a/GeoLib/IO/TINInterface.h b/GeoLib/IO/TINInterface.h
index 850d74a80f3bd6a3e11fab395e778320152afc8f..51962fe2f80b2c1832a559561dbe7c6374501b3f 100644
--- a/GeoLib/IO/TINInterface.h
+++ b/GeoLib/IO/TINInterface.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef TININTERFACE_H_
-#define TININTERFACE_H_
+#pragma once
 
 #include <string>
 #include <vector>
@@ -49,5 +48,3 @@ public:
 
 } // end namespace IO
 } // end namespace GeoLib
-
-#endif /* TININTERFACE_H_ */
diff --git a/GeoLib/IO/XmlIO/Boost/BoostXmlGmlInterface.h b/GeoLib/IO/XmlIO/Boost/BoostXmlGmlInterface.h
index e6ea4aa7f505e8b5014211120ccd5ab5c9ad94f0..9e478ba4285011df30050863c90b5739dea32eed 100644
--- a/GeoLib/IO/XmlIO/Boost/BoostXmlGmlInterface.h
+++ b/GeoLib/IO/XmlIO/Boost/BoostXmlGmlInterface.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef BOOSTXMLGMLINTERFACE_H_
-#define BOOSTXMLGMLINTERFACE_H_
+#pragma once
 
 #include <map>
 #include <string>
@@ -75,5 +74,3 @@ private:
 
 } // end namespace IO
 } // end namespace GeoLib
-
-#endif /* BOOSTXMLGMLINTERFACE_H_ */
diff --git a/GeoLib/IO/XmlIO/Qt/XmlGmlInterface.h b/GeoLib/IO/XmlIO/Qt/XmlGmlInterface.h
index 92abf6943d376a113adf1c32d2a04744d9f5f0fa..1f41bb3d9487b7e57f8be0bc72da69290588e777 100644
--- a/GeoLib/IO/XmlIO/Qt/XmlGmlInterface.h
+++ b/GeoLib/IO/XmlIO/Qt/XmlGmlInterface.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef XMLGMLINTERFACE_H
-#define XMLGMLINTERFACE_H
+#pragma once
 
 #include <QString>
 
@@ -90,5 +89,3 @@ private:
 
 } // end namespace IO
 } // end namespace BaseLib
-
-#endif // XMLGMLINTERFACE_H
diff --git a/GeoLib/IO/XmlIO/Qt/XmlStnInterface.h b/GeoLib/IO/XmlIO/Qt/XmlStnInterface.h
index 6f2372a50ad1f6238f1d865b08805750b85edf15..c9e0bff0d8dca8b573d2b463ed5a10e59ed48ac1 100644
--- a/GeoLib/IO/XmlIO/Qt/XmlStnInterface.h
+++ b/GeoLib/IO/XmlIO/Qt/XmlStnInterface.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef XMLSTNINTERFACE_H
-#define XMLSTNINTERFACE_H
+#pragma once
 
 #include <vector>
 
@@ -73,5 +72,3 @@ private:
 
 } // end namespace IO
 } // end namespace GeoLib
-
-#endif // XMLSTNINTERFACE_H
diff --git a/GeoLib/IO/XmlIO/Rapid/RapidStnInterface.h b/GeoLib/IO/XmlIO/Rapid/RapidStnInterface.h
index 70a32ae5d38dacc61193f0c4805b7d17a84522d1..0bf24f40c46030382d15bff61c0db2fbc7a73972 100644
--- a/GeoLib/IO/XmlIO/Rapid/RapidStnInterface.h
+++ b/GeoLib/IO/XmlIO/Rapid/RapidStnInterface.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef RAPIDXMLINTERFACE_H
-#define RAPIDXMLINTERFACE_H
+#pragma once
 
 #include <string>
 #include <vector>
@@ -51,5 +50,3 @@ private:
 
 } // IO
 } // GeoLib
-
-#endif // RAPIDXMLINTERFACE_H
diff --git a/GeoLib/IO/readGeometryFromFile.h b/GeoLib/IO/readGeometryFromFile.h
index 584b9aea2bfa2b3c875219081a615e90f3467d14..15c40fdccd49d873ea7da1370c156374b24e6807 100644
--- a/GeoLib/IO/readGeometryFromFile.h
+++ b/GeoLib/IO/readGeometryFromFile.h
@@ -8,8 +8,7 @@
  *
  */
 
-#ifndef READGEOMETRYFROMFILE_H
-#define READGEOMETRYFROMFILE_H
+#pragma once
 
 #include <string>
 
@@ -26,5 +25,3 @@ namespace IO
     readGeometryFromFile(std::string const& fname, GeoLib::GEOObjects & geo_objs);
 }
 }
-
-#endif // READGEOMETRYFROMFILE_H
diff --git a/GeoLib/IO/writeGeometryToFile.h b/GeoLib/IO/writeGeometryToFile.h
index ab1da24cdc87e4a0f0180c6644d6386a2c6e8a54..a669cee45bce21b9fda8196e15d470a2a81e6a4d 100644
--- a/GeoLib/IO/writeGeometryToFile.h
+++ b/GeoLib/IO/writeGeometryToFile.h
@@ -8,8 +8,7 @@
  *
  */
 
-#ifndef WRITEGEOMETRYTOFILE_H
-#define WRITEGEOMETRYTOFILE_H
+#pragma once
 
 #include <string>
 
@@ -28,5 +27,3 @@ void writeGeometryToFile(std::string const& geo_name,
     GeoLib::GEOObjects& geo_objs, std::string const& fname);
 }
 }
-
-#endif // WRITEGEOMETRYTOFILE_H
diff --git a/GeoLib/LineSegment.h b/GeoLib/LineSegment.h
index 76800a063399faba1403067634986388ac10ae6c..bb04e127c49aa36ac8e2e10abc5d5331efa8ef81 100644
--- a/GeoLib/LineSegment.h
+++ b/GeoLib/LineSegment.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/LICENSE.txt
  */
 
-#ifndef LINESEGMENT_H_
-#define LINESEGMENT_H_
+#pragma once
 
 #include "Point.h"
 
@@ -60,4 +59,3 @@ std::ostream& operator<<(std::ostream& os,
 bool operator==(LineSegment const& s0, LineSegment const& s1);
 
 }
-#endif
diff --git a/GeoLib/MinimalBoundingSphere.h b/GeoLib/MinimalBoundingSphere.h
index d23882e6e753584b96afa06f13dacf3780943bee..b16b5e2d2f29d3d44c10161223d5df5e906ab0b3 100644
--- a/GeoLib/MinimalBoundingSphere.h
+++ b/GeoLib/MinimalBoundingSphere.h
@@ -13,8 +13,7 @@
  *
  */
 
-#ifndef MINIMALBOUNDINGSPHERE_H_
-#define MINIMALBOUNDINGSPHERE_H_
+#pragma once
 
 #include <vector>
 
@@ -86,5 +85,3 @@ private:
 };
 
 } // namespace
-
-#endif /* MINIMALBOUNDINGSPHERE_H_ */
diff --git a/GeoLib/OctTree.h b/GeoLib/OctTree.h
index ad9c32491ff680e893603f844269bc9646dea85a..54dde3f2de13f2e7fb76346a2420ae036ca421ce 100644
--- a/GeoLib/OctTree.h
+++ b/GeoLib/OctTree.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef OCTTREE_H_
-#define OCTTREE_H_
+#pragma once
 
 #include <cstdint>
 
@@ -149,5 +148,3 @@ private:
 } // end namespace GeoLib
 
 #include "OctTree-impl.h"
-
-#endif /* OCTTREE_H_ */
diff --git a/GeoLib/Point.h b/GeoLib/Point.h
index 0645e91af0651c3834b93d84e7afcdd6c0fc30a0..3d61d4ee2b1a2cbb3c0cb6d5c2c94370a63deaef 100644
--- a/GeoLib/Point.h
+++ b/GeoLib/Point.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef POINT_H_
-#define POINT_H_
+#pragma once
 
 // GeoLib
 #include "GeoObject.h"
@@ -62,6 +61,3 @@ protected:
 };
 
 }
-
-#endif /* POINT_H_ */
-
diff --git a/GeoLib/PointVec.h b/GeoLib/PointVec.h
index d382ac1628d2e19de6391619a9d12bfb44da184e..3c26bf00750a9ed23edc70142c4aacbd5665222d 100644
--- a/GeoLib/PointVec.h
+++ b/GeoLib/PointVec.h
@@ -22,8 +22,7 @@
 #include <string>
 #include <vector>
 
-#ifndef POINTVEC_H_
-#define POINTVEC_H_
+#pragma once
 
 #include "TemplateVec.h"
 #include "OctTree.h"
@@ -146,5 +145,3 @@ private:
     std::unique_ptr<GeoLib::OctTree<GeoLib::Point, 16>> _oct_tree;
 };
 } // end namespace
-
-#endif /* POINTVEC_H_ */
diff --git a/GeoLib/Polygon.h b/GeoLib/Polygon.h
index 617304ff918535530b4a557dd4627bfcd023924b..08a7267f4b8741fdc882901864d54683d4c3a6a3 100644
--- a/GeoLib/Polygon.h
+++ b/GeoLib/Polygon.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef POLYGON_H_
-#define POLYGON_H_
+#pragma once
 
 #include <list>
 #include <vector>
@@ -167,5 +166,3 @@ GeoLib::Polygon* createPolygonFromCircle (GeoLib::Point const& middle_pnt,
 bool operator==(Polygon const& lhs, Polygon const& rhs);
 
 } // end namespace GeoLib
-
-#endif /* POLYGON_H_ */
diff --git a/GeoLib/PolygonWithSegmentMarker.h b/GeoLib/PolygonWithSegmentMarker.h
index b61ad2830b376645d40d53b0d34b83b0959769d0..6d91c215ad8a3ad5ee3cb5c4bb38bb1a4c8ad664 100644
--- a/GeoLib/PolygonWithSegmentMarker.h
+++ b/GeoLib/PolygonWithSegmentMarker.h
@@ -8,8 +8,7 @@
  *
  */
 
-#ifndef POLYGONWITHSEGMENTMARKER_H_
-#define POLYGONWITHSEGMENTMARKER_H_
+#pragma once
 
 #include "Polygon.h"
 
@@ -53,5 +52,3 @@ private:
 };
 
 } // end namespace GeoLib
-
-#endif /* POLYGONWITHSEGMENTMARKER_H_ */
diff --git a/GeoLib/Polyline.h b/GeoLib/Polyline.h
index 72fc6ce30c747e0fb86ce7f3b2cd253b7f41e3ac..5113d1e085fbc9516c196874ce790d1c65e62fab 100644
--- a/GeoLib/Polyline.h
+++ b/GeoLib/Polyline.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef POLYLINE_H_
-#define POLYLINE_H_
+#pragma once
 
 #include <cmath>
 #include <vector>
@@ -264,5 +263,3 @@ bool operator==(Polyline const& lhs, Polyline const& rhs);
 bool pointsAreIdentical(const std::vector<Point*> &pnt_vec, std::size_t i, std::size_t j,
                         double prox);
 } // end namespace
-
-#endif /* POLYLINE_H_ */
diff --git a/GeoLib/PolylineVec.h b/GeoLib/PolylineVec.h
index 2e73fb3b1dbf21e3776a4e1f4aa5756bcc161292..cd09252f3ae0080b8961a26aebf765d55e18fc44 100644
--- a/GeoLib/PolylineVec.h
+++ b/GeoLib/PolylineVec.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef POLYLINEVEC_H_
-#define POLYLINEVEC_H_
+#pragma once
 
 #include "TemplateVec.h"
 #include "Polyline.h"
@@ -30,5 +29,3 @@ namespace GeoLib {
 typedef TemplateVec<Polyline> PolylineVec;
 
 } // end namespace
-
-#endif /* POLYLINEVEC_H_ */
diff --git a/GeoLib/PolylineWithSegmentMarker.h b/GeoLib/PolylineWithSegmentMarker.h
index f5e794a2c04238e2d88950ae7934140179b7d5f7..a7f72b4da0d60c1d641ab86c4ab75c8deef617bf 100644
--- a/GeoLib/PolylineWithSegmentMarker.h
+++ b/GeoLib/PolylineWithSegmentMarker.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef POLYLINEWITHSEGMENTMARKER_H_
-#define POLYLINEWITHSEGMENTMARKER_H_
+#pragma once
 
 #include "Polyline.h"
 
@@ -59,5 +58,3 @@ private:
 };
 
 }
-
-#endif /* POLYLINEWITHSEGMENTMARKER_H_ */
diff --git a/GeoLib/QuadTree.h b/GeoLib/QuadTree.h
index 37d90748c7b1ec9f231b0e9d2e8ec36af8fcec1b..de71d952ef123e0d13abca6c079f404f524fd59f 100644
--- a/GeoLib/QuadTree.h
+++ b/GeoLib/QuadTree.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef QUADTREE_H_
-#define QUADTREE_H_
+#pragma once
 
 #include <limits>
 
@@ -494,5 +493,3 @@ private:
     const std::size_t _max_points_per_leaf;
 };
 }
-
-#endif /* QUADTREE_H_ */
diff --git a/GeoLib/Raster.h b/GeoLib/Raster.h
index a69a44a3db103158124c355f94d3456030a43da8..386ab2ecb59c2a7532b04202d0577b811c9b7ad6 100644
--- a/GeoLib/Raster.h
+++ b/GeoLib/Raster.h
@@ -11,8 +11,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef RASTER_H_
-#define RASTER_H_
+#pragma once
 
 #include "Surface.h"
 
@@ -105,5 +104,3 @@ private:
 };
 
 }
-
-#endif /* RASTER_H_ */
diff --git a/GeoLib/SensorData.h b/GeoLib/SensorData.h
index c5050e055c54d193584636d84ea54ee514076e8b..b8ec6186fe38da0384d6ba279f194bf3a47d115b 100644
--- a/GeoLib/SensorData.h
+++ b/GeoLib/SensorData.h
@@ -12,9 +12,7 @@
  *
  */
 
-
-#ifndef SENSORDATA_H
-#define SENSORDATA_H
+#pragma once
 
 #include <cstddef>
 #include <string>
@@ -130,6 +128,3 @@ private:
     std::vector< std::vector<float>* > _data_vecs;
 
 };
-
-#endif //SENSORDATA_H
-
diff --git a/GeoLib/SimplePolygonTree.h b/GeoLib/SimplePolygonTree.h
index f7f581174d62cb8dee06a4d20cd05baeb84d9375..eb53dd8a786565f83a246a2042ec055aac906845 100644
--- a/GeoLib/SimplePolygonTree.h
+++ b/GeoLib/SimplePolygonTree.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef SIMPLEPOLYGONTREE_H_
-#define SIMPLEPOLYGONTREE_H_
+#pragma once
 
 #include <list>
 
@@ -110,5 +109,3 @@ void createPolygonTrees (std::list<POLYGONTREETYPE*>& list_of_simple_polygon_hie
 
 
 } // end namespace GeoLib
-
-#endif /* SIMPLEPOLYGONTREE_H_ */
diff --git a/GeoLib/Station.h b/GeoLib/Station.h
index e720d014b50bf5ace55d4b4098ca7b28bd7c04e7..adca976c61b3cffe809e6d1f62cf01eec2b570e7 100644
--- a/GeoLib/Station.h
+++ b/GeoLib/Station.h
@@ -12,9 +12,7 @@
  *
  */
 
-
-#ifndef GEO_STATION_H
-#define GEO_STATION_H
+#pragma once
 
 #include <string>
 
@@ -107,5 +105,3 @@ private:
 
 bool isStation(GeoLib::Point const* pnt);
 } // namespace
-
-#endif // GEO_STATION_H
diff --git a/GeoLib/StationBorehole.h b/GeoLib/StationBorehole.h
index 05e9252faf25e65cdd4c29f169d7bfd7d2968c5e..725d62c80f605eba399dae07c6a059031f1889fb 100644
--- a/GeoLib/StationBorehole.h
+++ b/GeoLib/StationBorehole.h
@@ -12,9 +12,7 @@
  *
  */
 
-
-#ifndef GEO_STATIONBOREHOLE_H
-#define GEO_STATIONBOREHOLE_H
+#pragma once
 
 #include "Station.h"
 
@@ -120,5 +118,3 @@ private:
 bool isBorehole(GeoLib::Point const* pnt);
 
 } // namespace
-
-#endif // GEO_STATIONBOREHOLE_H
diff --git a/GeoLib/Surface.h b/GeoLib/Surface.h
index fcf24f7e2fd4bd4d48f4d9de61177c29714a9bbd..0dccba5e65b73941c9986a66dec807cc5e327b00 100644
--- a/GeoLib/Surface.h
+++ b/GeoLib/Surface.h
@@ -8,8 +8,7 @@
  *
  */
 
-#ifndef SURFACE_H_
-#define SURFACE_H_
+#pragma once
 
 #include <vector>
 #include <memory>
@@ -104,5 +103,3 @@ protected:
     mutable std::unique_ptr<SurfaceGrid> _surface_grid;
 };
 }
-
-#endif /* SURFACE_H_ */
diff --git a/GeoLib/SurfaceGrid.h b/GeoLib/SurfaceGrid.h
index 85741eb60549ecc81064271130e96071fc63f7b1..55cc76cd85e287d89c8b0eba322174b0e55a670e 100644
--- a/GeoLib/SurfaceGrid.h
+++ b/GeoLib/SurfaceGrid.h
@@ -9,8 +9,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef SURFACEGRID_H_
-#define SURFACEGRID_H_
+#pragma once
 
 #include <array>
 #include <limits>
@@ -45,5 +44,3 @@ private:
 };
 
 } // end namespace GeoLib
-
-#endif /* SURFACEGRID_H_ */
diff --git a/GeoLib/SurfaceVec.h b/GeoLib/SurfaceVec.h
index b14bcf7812802c62dc9795386e4c2cbb53ec7d1a..abd452a3a83ce1ecb0977d5ff6065d79d8c0be80 100644
--- a/GeoLib/SurfaceVec.h
+++ b/GeoLib/SurfaceVec.h
@@ -12,9 +12,7 @@
  *
  */
 
-
-#ifndef SURFACEVEC_H_
-#define SURFACEVEC_H_
+#pragma once
 
 #include "TemplateVec.h"
 #include "Surface.h"
@@ -29,5 +27,3 @@ namespace GeoLib {
 typedef TemplateVec<Surface> SurfaceVec;
 
 } // end namespace
-
-#endif /* SURFACEVEC_H_ */
diff --git a/GeoLib/TemplateVec.h b/GeoLib/TemplateVec.h
index f2263aea19f9c684a7467cf29ab2566c254a001e..36a0ba2ab4ca7b96e47e1eecd87014fdb84404c8 100644
--- a/GeoLib/TemplateVec.h
+++ b/GeoLib/TemplateVec.h
@@ -13,8 +13,7 @@
  *
  */
 
-#ifndef TEMPLATEVEC_H_
-#define TEMPLATEVEC_H_
+#pragma once
 
 #include <algorithm>
 #include <cstdlib>
@@ -238,5 +237,3 @@ protected:
     NameIdMap* _name_id_map;
 };
 } // end namespace GeoLib
-
-#endif /* TEMPLATEVEC_H_ */
diff --git a/GeoLib/Triangle.h b/GeoLib/Triangle.h
index 0baeaa07ce5f9ef287ae0c761433b741b55c2977..9ed82555ac717c2789496601d4b0aea9d7d462eb 100644
--- a/GeoLib/Triangle.h
+++ b/GeoLib/Triangle.h
@@ -8,8 +8,7 @@
  *
  */
 
-#ifndef TRIANGLE_H_
-#define TRIANGLE_H_
+#pragma once
 
 #include <vector>
 
@@ -87,5 +86,3 @@ private:
 void getPlaneCoefficients(Triangle const& tri, double c[3]);
 
 } // end namespace GeoLib
-
-#endif /* TRIANGLE_H_ */
diff --git a/MaterialLib/Adsorption/Adsorption.h b/MaterialLib/Adsorption/Adsorption.h
index ca780a62469a82de8ef62e5d97429ba9828f245d..685d6bbfc417d7a9f5737d1fb2adf735b810fcf7 100644
--- a/MaterialLib/Adsorption/Adsorption.h
+++ b/MaterialLib/Adsorption/Adsorption.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef ADSORPTION_H
-#define ADSORPTION_H
+#pragma once
 
 #include <array>
 #include <cmath>
@@ -82,5 +81,3 @@ inline double dCurvePolyfrac(const double* coeffs, const double x)
 }
 
 }
-
-#endif // ADSORPTION_H
diff --git a/MaterialLib/Adsorption/Density100MPa.h b/MaterialLib/Adsorption/Density100MPa.h
index 2d9f80dcf1dc0c3b37adbe084121d2e6bb7a335d..ecd5d099abf90d3b66afc1a8bd0d6ac6e1f9b021 100644
--- a/MaterialLib/Adsorption/Density100MPa.h
+++ b/MaterialLib/Adsorption/Density100MPa.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATERIALSLIB_ADSORPTION_DENSITY100MPA_H
-#define MATERIALSLIB_ADSORPTION_DENSITY100MPA_H
+#pragma once
 
 #include "Adsorption.h"
 
@@ -25,4 +24,3 @@ public:
 };
 
 }
-#endif // MATERIALSLIB_ADSORPTION_DENSITY100MPA_H
diff --git a/MaterialLib/Adsorption/DensityConst.h b/MaterialLib/Adsorption/DensityConst.h
index ee78332e22d6bb188331971a70d8e4996a125490..97a20104426108fd716294111374a9237f9ef7be 100644
--- a/MaterialLib/Adsorption/DensityConst.h
+++ b/MaterialLib/Adsorption/DensityConst.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATERIALSLIB_ADSORPTION_DENSITYCONST_H
-#define MATERIALSLIB_ADSORPTION_DENSITYCONST_H
+#pragma once
 
 #include "Adsorption.h"
 
@@ -25,4 +24,3 @@ public:
 };
 
 }
-#endif // MATERIALSLIB_ADSORPTION_DENSITYCONST_H
diff --git a/MaterialLib/Adsorption/DensityCook.h b/MaterialLib/Adsorption/DensityCook.h
index 268bfc87e4b96e2083f30b55f1fbb33df7af2ba6..35722161f6c64937a914b0d2ec34ae6d755aed91 100644
--- a/MaterialLib/Adsorption/DensityCook.h
+++ b/MaterialLib/Adsorption/DensityCook.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATERIALSLIB_ADSORPTION_DENSITYCOOK_H
-#define MATERIALSLIB_ADSORPTION_DENSITYCOOK_H
+#pragma once
 
 #include "Adsorption.h"
 
@@ -54,4 +53,3 @@ inline double alphaTWaterDean(const double T_Ads)
 }
 
 }
-#endif // MATERIALSLIB_ADSORPTION_DENSITYCOOK_H
diff --git a/MaterialLib/Adsorption/DensityDubinin.h b/MaterialLib/Adsorption/DensityDubinin.h
index 84747caffa95cfe5148fc0952aa2241fa9deab1c..a66bb696bb83bcab6645c41284f78a978635e303 100644
--- a/MaterialLib/Adsorption/DensityDubinin.h
+++ b/MaterialLib/Adsorption/DensityDubinin.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATERIALSLIB_ADSORPTION_DENSITYDUBININ_H
-#define MATERIALSLIB_ADSORPTION_DENSITYDUBININ_H
+#pragma once
 
 #include "Adsorption.h"
 
@@ -25,4 +24,3 @@ public:
 };
 
 }
-#endif // MATERIALSLIB_ADSORPTION_DENSITYDUBININ_H
diff --git a/MaterialLib/Adsorption/DensityHauer.h b/MaterialLib/Adsorption/DensityHauer.h
index 518e415aca72149975eda003b1c7447bcef194fc..1bf9d1995c53b63cf9b9a19f65125c26c98131f4 100644
--- a/MaterialLib/Adsorption/DensityHauer.h
+++ b/MaterialLib/Adsorption/DensityHauer.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATERIALSLIB_ADSORPTION_DENSITYHAUER_H
-#define MATERIALSLIB_ADSORPTION_DENSITYHAUER_H
+#pragma once
 
 #include "Adsorption.h"
 #include "DensityCook.h"
@@ -34,4 +33,3 @@ inline double rhoWaterHauer(const double T_Ads)
 }
 
 }
-#endif // MATERIALSLIB_ADSORPTION_DENSITYHAUER_H
diff --git a/MaterialLib/Adsorption/DensityLegacy.h b/MaterialLib/Adsorption/DensityLegacy.h
index 9fa67e626680aa6b383dc73b6cac03e2ff153e18..b75632a8393a5d55d3897f39b38e8eb3149dc366 100644
--- a/MaterialLib/Adsorption/DensityLegacy.h
+++ b/MaterialLib/Adsorption/DensityLegacy.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATERIALSLIB_ADSORPTION_DENSITYLEGACY_H
-#define MATERIALSLIB_ADSORPTION_DENSITYLEGACY_H
+#pragma once
 
 #include "Adsorption.h"
 
@@ -25,4 +24,3 @@ public:
 };
 
 }
-#endif // MATERIALSLIB_ADSORPTION_DENSITYLEGACY_H
diff --git a/MaterialLib/Adsorption/DensityMette.h b/MaterialLib/Adsorption/DensityMette.h
index 3e27f43f365763944737a8ed3b9faeb6fcd44f35..0ec144f1f57fbebc374b2e5f871448e199064f3d 100644
--- a/MaterialLib/Adsorption/DensityMette.h
+++ b/MaterialLib/Adsorption/DensityMette.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATERIALSLIB_ADSORPTION_DENSITYMETTE_H
-#define MATERIALSLIB_ADSORPTION_DENSITYMETTE_H
+#pragma once
 
 #include "Adsorption.h"
 
@@ -25,4 +24,3 @@ public:
 };
 
 }
-#endif // MATERIALSLIB_ADSORPTION_DENSITYMETTE_H
diff --git a/MaterialLib/Adsorption/DensityNunez.h b/MaterialLib/Adsorption/DensityNunez.h
index 78b9ad69e397bd7f366732376c2e36cdc9dba7c2..7e4e4e71b8805ef8333247aa1a7ec33cff93f597 100644
--- a/MaterialLib/Adsorption/DensityNunez.h
+++ b/MaterialLib/Adsorption/DensityNunez.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATERIALSLIB_ADSORPTION_DENSITYNUNEZ_H
-#define MATERIALSLIB_ADSORPTION_DENSITYNUNEZ_H
+#pragma once
 
 #include "Adsorption.h"
 
@@ -25,4 +24,3 @@ public:
 };
 
 }
-#endif // MATERIALSLIB_ADSORPTION_DENSITYNUNEZ_H
diff --git a/MaterialLib/Adsorption/Reaction.h b/MaterialLib/Adsorption/Reaction.h
index 004b03110e9c1879c80cf72dfef357805b54485a..2c0a157a6ce733e86f33d14e80959558db679e0f 100644
--- a/MaterialLib/Adsorption/Reaction.h
+++ b/MaterialLib/Adsorption/Reaction.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATERIALSLIB_ADSORPTION_REACTION_H
-#define MATERIALSLIB_ADSORPTION_REACTION_H
+#pragma once
 
 #include <memory>
 
@@ -35,4 +34,3 @@ public:
 };
 
 }
-#endif // MATERIALSLIB_ADSORPTION_REACTION_H
diff --git a/MaterialLib/Adsorption/ReactionCaOH2.h b/MaterialLib/Adsorption/ReactionCaOH2.h
index 4cc7543eee300b5f3464df0072af666273bd5f9b..16cbc79efd8302f317a92433661c5efd61c0ce7d 100644
--- a/MaterialLib/Adsorption/ReactionCaOH2.h
+++ b/MaterialLib/Adsorption/ReactionCaOH2.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATERIALSLIB_ADSORPTION_REACTIONCAOH2_H
-#define MATERIALSLIB_ADSORPTION_REACTIONCAOH2_H
+#pragma once
 
 #include "BaseLib/ConfigTree.h"
 #include "Reaction.h"
@@ -84,4 +83,3 @@ public:
 };
 
 }
-#endif // MATERIALSLIB_ADSORPTION_REACTIONCAOH2_H
diff --git a/MaterialLib/Adsorption/ReactionInert.h b/MaterialLib/Adsorption/ReactionInert.h
index bc49787fb0897502f0d6f3fd44449caa535b1996..3e3a05052c1a970f99b3d03ee18b793342b0d5a2 100644
--- a/MaterialLib/Adsorption/ReactionInert.h
+++ b/MaterialLib/Adsorption/ReactionInert.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATERIALSLIB_ADSORPTION_REACTIONINERT_H
-#define MATERIALSLIB_ADSORPTION_REACTIONINERT_H
+#pragma once
 
 #include "BaseLib/Error.h"
 
@@ -34,4 +33,3 @@ public:
 };
 
 }
-#endif // MATERIALSLIB_ADSORPTION_REACTIONINERT_H
diff --git a/MaterialLib/Adsorption/ReactionSinusoidal.h b/MaterialLib/Adsorption/ReactionSinusoidal.h
index 6f40dd2d46cace7e794b7d2757f3d8454a518d90..00179611a1cf1241a9c73bac35d21817b41ae72d 100644
--- a/MaterialLib/Adsorption/ReactionSinusoidal.h
+++ b/MaterialLib/Adsorption/ReactionSinusoidal.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATERIALSLIB_ADSORPTION_REACTIONSINUSOIDAL_H
-#define MATERIALSLIB_ADSORPTION_REACTIONSINUSOIDAL_H
+#pragma once
 
 #include <logog/include/logog.hpp>
 
@@ -45,4 +44,3 @@ private:
 };
 
 }
-#endif // MATERIALSLIB_ADSORPTION_REACTIONSINUSOIDAL_H
diff --git a/MaterialLib/Fluid/ConstantFluidProperty.h b/MaterialLib/Fluid/ConstantFluidProperty.h
index 4852800407471ca8d61998300206fe6dfd0ddecd..d3ddc608374d498dc9633b5958ea622bbd455761 100644
--- a/MaterialLib/Fluid/ConstantFluidProperty.h
+++ b/MaterialLib/Fluid/ConstantFluidProperty.h
@@ -10,8 +10,7 @@
  * Created on August 15, 2016, 12:11 PM
  */
 
-#ifndef CONSTANTFLUIDPROPERTY_H
-#define CONSTANTFLUIDPROPERTY_H
+#pragma once
 
 #include "FluidProperty.h"
 
@@ -57,4 +56,3 @@ private:
 
 }  // end namespace
 }  // end namespace
-#endif /* CONSTANTFLUIDPROPERTY_H */
diff --git a/MaterialLib/Fluid/Density/IdealGasLaw.h b/MaterialLib/Fluid/Density/IdealGasLaw.h
index f8925d1f97e86c922d1bb50b9d883411001f2281..5445f439f5dca77a0286f96061db0d7fd2e58de9 100644
--- a/MaterialLib/Fluid/Density/IdealGasLaw.h
+++ b/MaterialLib/Fluid/Density/IdealGasLaw.h
@@ -12,8 +12,7 @@
                See accompanying file LICENSE.txt or
                http://www.opengeosys.org/project/license
  */
-#ifndef IDEAL_GAS_LAW_H_
-#define IDEAL_GAS_LAW_H_
+#pragma once
 
 #include <cassert>
 #include <string>
@@ -90,4 +89,3 @@ private:
 };
 }  // end namespace
 }  // end namespace
-#endif
diff --git a/MaterialLib/Fluid/Density/LinearTemperatureDependentDensity.h b/MaterialLib/Fluid/Density/LinearTemperatureDependentDensity.h
index 75b29615ab8bd5423a02e7f554b31c6bea7ab341..3d7327d5607c24fed51285689120bc81bbc8d350 100644
--- a/MaterialLib/Fluid/Density/LinearTemperatureDependentDensity.h
+++ b/MaterialLib/Fluid/Density/LinearTemperatureDependentDensity.h
@@ -11,8 +11,7 @@
  * Created on August 10, 2016, 11:34 AM
  */
 
-#ifndef LINEARTEMPERATUREDEPENDENTDENSITY_H
-#define LINEARTEMPERATUREDEPENDENTDENSITY_H
+#pragma once
 
 #include <string>
 
@@ -74,5 +73,3 @@ private:
 
 }  // end namespace
 }  // end namespace
-
-#endif /* LINEARTEMPERATUREDEPENDENTDENSITY_H */
diff --git a/MaterialLib/Fluid/Density/LiquidDensity.h b/MaterialLib/Fluid/Density/LiquidDensity.h
index f55bc9041ad4f0e20cde221b24fca8679eebccbb..5bfd617fff9241cd5a59b0b34545ddce9309a5f5 100644
--- a/MaterialLib/Fluid/Density/LiquidDensity.h
+++ b/MaterialLib/Fluid/Density/LiquidDensity.h
@@ -11,8 +11,7 @@
  * Created on August 4, 2016, 10:15 AM
  */
 
-#ifndef LIQUIDDENSITY_H
-#define LIQUIDDENSITY_H
+#pragma once
 
 #include <vector>
 
@@ -141,5 +140,3 @@ private:
 
 }  // end of namespace
 }  // end of namespace
-
-#endif /* LIQUIDDENSITY_H */
diff --git a/MaterialLib/Fluid/Density/WaterDensityIAPWSIF97Region1.h b/MaterialLib/Fluid/Density/WaterDensityIAPWSIF97Region1.h
index a658fd6dfbd341e3defd00140ebb99b601e1dc96..ff2dbbe088c41df512f959281b3dcad9edc3b151 100644
--- a/MaterialLib/Fluid/Density/WaterDensityIAPWSIF97Region1.h
+++ b/MaterialLib/Fluid/Density/WaterDensityIAPWSIF97Region1.h
@@ -10,8 +10,7 @@
  * Created on December 8, 2016, 4:19 PM
  */
 
-#ifndef OGS_WATER_DENSITY_IAPWSIF97_REGION1_H
-#define OGS_WATER_DENSITY_IAPWSIF97_REGION1_H
+#pragma once
 
 #include <string>
 
@@ -93,4 +92,3 @@ private:
 
 }  // end of namespace
 }  // end of namespace
-#endif /* OGS_WATER_DENSITY_IAPWSIF97_REGION1_H */
diff --git a/MaterialLib/Fluid/Density/createFluidDensityModel.h b/MaterialLib/Fluid/Density/createFluidDensityModel.h
index e6c08a1061c3aa10c87181ab9e46f8396247e02c..df3e7fb905742d6a0c1ac8cf0862691a87d8e1f3 100644
--- a/MaterialLib/Fluid/Density/createFluidDensityModel.h
+++ b/MaterialLib/Fluid/Density/createFluidDensityModel.h
@@ -8,8 +8,7 @@
                See accompanying file LICENSE.txt or
                http://www.opengeosys.org/project/license
 */
-#ifndef CREATE_FLUID_DENSITY_MODEL_H_
-#define CREATE_FLUID_DENSITY_MODEL_H_
+#pragma once
 
 #include <memory>
 
@@ -27,4 +26,3 @@ std::unique_ptr<FluidProperty> createFluidDensityModel(
     BaseLib::ConfigTree const& config);
 }
 }  // end namespace
-#endif
diff --git a/MaterialLib/Fluid/FluidProperty.h b/MaterialLib/Fluid/FluidProperty.h
index cf2cdd292c3f7e11d348dce8509da4c06d012c0b..ec3af66e9f7ba75de24741b24faaba077a447262 100644
--- a/MaterialLib/Fluid/FluidProperty.h
+++ b/MaterialLib/Fluid/FluidProperty.h
@@ -10,8 +10,7 @@
  * Created on August 12, 2016, 3:34 PM
  */
 
-#ifndef FLUIDPROPERTY_H
-#define FLUIDPROPERTY_H
+#pragma once
 
 #include <array>
 #include <string>
@@ -58,5 +57,3 @@ public:
 
 }  // end namespace
 }  // end namespace
-
-#endif /* FLUIDPROPERTY_H */
diff --git a/MaterialLib/Fluid/FluidPropertyHeaders.h b/MaterialLib/Fluid/FluidPropertyHeaders.h
index 111f5c84302dadafbdd4841b9de4398b75ffe3d3..da18197b86e10b4f7d0d58b120249ba06bd3bfaa 100644
--- a/MaterialLib/Fluid/FluidPropertyHeaders.h
+++ b/MaterialLib/Fluid/FluidPropertyHeaders.h
@@ -11,10 +11,7 @@
  * Created on August 18, 2016, 11:10 AM
  */
 
-#ifndef FLUIDPROPERTYHEADERS_H
-#define FLUIDPROPERTYHEADERS_H
+#pragma once
 
 #include "Density/createFluidDensityModel.h"
 #include "Viscosity/createViscosityModel.h"
-
-#endif /* FLUIDPROPERTYHEADERS_H */
diff --git a/MaterialLib/Fluid/GibbsFreeEnergy/DimensionLessGibbsFreeEnergyRegion1.h b/MaterialLib/Fluid/GibbsFreeEnergy/DimensionLessGibbsFreeEnergyRegion1.h
index f8b1f143e30161734a5fd96f75e274ce396389e3..0b32f47d3ad12200148afe085e0d09f9b92519dc 100644
--- a/MaterialLib/Fluid/GibbsFreeEnergy/DimensionLessGibbsFreeEnergyRegion1.h
+++ b/MaterialLib/Fluid/GibbsFreeEnergy/DimensionLessGibbsFreeEnergyRegion1.h
@@ -12,8 +12,7 @@
  * Created on December 8, 2016, 12:31 PM
  */
 
-#ifndef OGS_DIMENSION_LESS_GIBBS_FREE_ENERGY_REGION1_H
-#define OGS_DIMENSION_LESS_GIBBS_FREE_ENERGY_REGION1_H
+#pragma once
 
 namespace MaterialLib
 {
@@ -97,4 +96,3 @@ public:
 
 }  // end namespace
 }  // end namespace
-#endif /* OGS_DIMENSION_LESS_GIBBS_FREE_ENERGY_REGION1_H */
diff --git a/MaterialLib/Fluid/Viscosity/LinearPressureDependentViscosity.h b/MaterialLib/Fluid/Viscosity/LinearPressureDependentViscosity.h
index 29d560925ea231a9ebb2c5d94479e0444f1739fd..0b4dc08e8401488b01c7ebbfd492b2c5e1476fc2 100644
--- a/MaterialLib/Fluid/Viscosity/LinearPressureDependentViscosity.h
+++ b/MaterialLib/Fluid/Viscosity/LinearPressureDependentViscosity.h
@@ -9,8 +9,7 @@
  *
  *   \file  LinearPressureDependentViscosity.h
  */
-#ifndef LINEAR_PRESSURE_DEPENDENT_VISCOSITY_H_
-#define LINEAR_PRESSURE_DEPENDENT_VISCOSITY_H_
+#pragma once
 
 #include <string>
 
@@ -85,4 +84,3 @@ private:
 
 }  // end namespace
 }  // end namespace
-#endif
diff --git a/MaterialLib/Fluid/Viscosity/TemperatureDependentViscosity.h b/MaterialLib/Fluid/Viscosity/TemperatureDependentViscosity.h
index 0af468d58cbde7a21a727f03eedd351fe2cc62f4..fc65e3980115f1bc0cddbe954283611a2c777e35 100644
--- a/MaterialLib/Fluid/Viscosity/TemperatureDependentViscosity.h
+++ b/MaterialLib/Fluid/Viscosity/TemperatureDependentViscosity.h
@@ -12,8 +12,7 @@
  *  Created on August 10, 2016, 10:45 AM
  */
 
-#ifndef TEMPERATUREDEPENDENTVISCOSITY_H
-#define TEMPERATUREDEPENDENTVISCOSITY_H
+#pragma once
 
 #include <string>
 #include <cmath>
@@ -93,5 +92,3 @@ private:
 
 }  // end namespace
 }  // end namespace
-
-#endif /* TEMPERATUREDEPENDENTVISCOSITY_H */
diff --git a/MaterialLib/Fluid/Viscosity/VogelsLiquidDynamicViscosity.h b/MaterialLib/Fluid/Viscosity/VogelsLiquidDynamicViscosity.h
index 44e490ef8dbfff87848a147c0b6370789477cd6a..ed94b0fb825c6a06ddd7256f2a209104beb7d3a4 100644
--- a/MaterialLib/Fluid/Viscosity/VogelsLiquidDynamicViscosity.h
+++ b/MaterialLib/Fluid/Viscosity/VogelsLiquidDynamicViscosity.h
@@ -11,8 +11,7 @@
  *
  */
 
-#ifndef VOGELS_LIQUID_DYNAMIC_VISCOSITY_H_
-#define VOGELS_LIQUID_DYNAMIC_VISCOSITY_H_
+#pragma once
 
 #include <string>
 #include <vector>
@@ -112,4 +111,3 @@ struct VogelsViscosityConstantsCH4
 
 }  // end namespace
 }  // end namespace
-#endif
diff --git a/MaterialLib/Fluid/Viscosity/WaterViscosityIAPWS.h b/MaterialLib/Fluid/Viscosity/WaterViscosityIAPWS.h
index 918eddafa798b341d4562ca5b552e9171b60e90c..356383bb120800829aaf2797d79b5656ea2f4c75 100644
--- a/MaterialLib/Fluid/Viscosity/WaterViscosityIAPWS.h
+++ b/MaterialLib/Fluid/Viscosity/WaterViscosityIAPWS.h
@@ -14,8 +14,7 @@
  * Created on December 1, 2016, 1:41 PM
  */
 
-#ifndef OGS_WATER_VISCOSITY_IAPWS_H
-#define OGS_WATER_VISCOSITY_IAPWS_H
+#pragma once
 
 #include <string>
 
@@ -85,5 +84,3 @@ private:
 
 }  // end namespace
 }  // end namespace
-
-#endif /* OGS_WATER_VISCOSITY_IAPWS_H */
diff --git a/MaterialLib/Fluid/Viscosity/createViscosityModel.h b/MaterialLib/Fluid/Viscosity/createViscosityModel.h
index dd4f972aa7151a717b1e9d1288ad67216f1ae712..f39dd57a06f16d5c1627e939f020afe7684cc449 100644
--- a/MaterialLib/Fluid/Viscosity/createViscosityModel.h
+++ b/MaterialLib/Fluid/Viscosity/createViscosityModel.h
@@ -11,8 +11,7 @@
  *
  */
 
-#ifndef CREATE_VISCOSITY_MODEL_H_
-#define CREATE_VISCOSITY_MODEL_H_
+#pragma once
 
 #include <memory>
 
@@ -31,4 +30,3 @@ std::unique_ptr<FluidProperty> createViscosityModel(
 
 }  // end namespace
 }  // end namespace
-#endif
diff --git a/MaterialLib/FractureModels/CreateLinearElasticIsotropic.h b/MaterialLib/FractureModels/CreateLinearElasticIsotropic.h
index c548d9a156208616110c48d50691130dc1be3f0f..18acc5170587d03c8c1de19777bcaaecaf8ee4e3 100644
--- a/MaterialLib/FractureModels/CreateLinearElasticIsotropic.h
+++ b/MaterialLib/FractureModels/CreateLinearElasticIsotropic.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATERIALLIB_FRACTURE_CREATELINEARELASTICISOTROPIC_H_
-#define MATERIALLIB_FRACTURE_CREATELINEARELASTICISOTROPIC_H_
+#pragma once
 
 #include "FractureModelBase.h"
 
@@ -25,5 +24,3 @@ createLinearElasticIsotropic(
 
 }  // namespace Fracture
 }  // namespace MaterialLib
-
-#endif
diff --git a/MaterialLib/FractureModels/CreateMohrCoulomb.h b/MaterialLib/FractureModels/CreateMohrCoulomb.h
index 70fc71f7b050cf4672d59757d41cc5747f8a91ae..4571647bc748d5cb171f12155a79c77638e683bb 100644
--- a/MaterialLib/FractureModels/CreateMohrCoulomb.h
+++ b/MaterialLib/FractureModels/CreateMohrCoulomb.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATERIALLIB_FRACTURE_CREATEMOHRCOULOMB_H_
-#define MATERIALLIB_FRACTURE_CREATEMOHRCOULOMB_H_
+#pragma once
 
 #include "FractureModelBase.h"
 
@@ -25,5 +24,3 @@ createMohrCoulomb(
 
 }  // namespace Fracture
 }  // namespace MaterialLib
-
-#endif
diff --git a/MaterialLib/FractureModels/FractureIdentity2.h b/MaterialLib/FractureModels/FractureIdentity2.h
index 3c43197649dd51171971fb4bd6f76c497d2db24e..538a51ab16dc45ac4cdcd157d7cf9f273efdcf9e 100644
--- a/MaterialLib/FractureModels/FractureIdentity2.h
+++ b/MaterialLib/FractureModels/FractureIdentity2.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATERIALLIB_FRACTURE_IDENTITY2_H_
-#define MATERIALLIB_FRACTURE_IDENTITY2_H_
+#pragma once
 
 #include <Eigen/Eigen>
 
@@ -32,5 +31,3 @@ extern template struct FractureIdentity2<3>;
 
 }  // namespace Fracture
 }  // namespace MaterialLib
-
-#endif // MATERIALLIB_FRACTURE_IDENTITY2_H_
diff --git a/MaterialLib/FractureModels/FractureModelBase.h b/MaterialLib/FractureModels/FractureModelBase.h
index 62a8314e0ac0ad7a3684a821a1a1eff803d6f6f9..f82f126f85041cf105458458b12626f0f7034226 100644
--- a/MaterialLib/FractureModels/FractureModelBase.h
+++ b/MaterialLib/FractureModels/FractureModelBase.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATERIALLIB_FRACTURE_FRACTUREMODELBASE_H_
-#define MATERIALLIB_FRACTURE_FRACTUREMODELBASE_H_
+#pragma once
 
 #include <Eigen/Eigen>
 
@@ -88,5 +87,3 @@ public:
 
 }  // namespace Fracture
 }  // namespace MaterialLib
-
-#endif
diff --git a/MaterialLib/FractureModels/LinearElasticIsotropic.h b/MaterialLib/FractureModels/LinearElasticIsotropic.h
index 089447bc41d690db12f14e01d575c0e6e2400514..7c44ede3f584f2752ca600418adb7cd75af226f8 100644
--- a/MaterialLib/FractureModels/LinearElasticIsotropic.h
+++ b/MaterialLib/FractureModels/LinearElasticIsotropic.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATERIALLIB_FRACTURE_LINEARELASTICISOTROPIC_H_
-#define MATERIALLIB_FRACTURE_LINEARELASTICISOTROPIC_H_
+#pragma once
 
 #include <Eigen/Eigen>
 
@@ -100,5 +99,3 @@ extern template class LinearElasticIsotropic<2>;
 extern template class LinearElasticIsotropic<3>;
 }  // namespace Fractrue
 }  // namespace MaterialLib
-
-#endif
diff --git a/MaterialLib/FractureModels/MohrCoulomb.h b/MaterialLib/FractureModels/MohrCoulomb.h
index b372bde219e15ba0dd6533443d33aad6eb9f0932..a16744bd5acb38c6db4f5dbc4dd756868e487300 100644
--- a/MaterialLib/FractureModels/MohrCoulomb.h
+++ b/MaterialLib/FractureModels/MohrCoulomb.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATERIALLIB_FRACTURE_MOHRCOULOMB_H_
-#define MATERIALLIB_FRACTURE_MOHRCOULOMB_H_
+#pragma once
 
 #include <Eigen/Eigen>
 
@@ -111,5 +110,3 @@ extern template class MohrCoulomb<2>;
 extern template class MohrCoulomb<3>;
 }  // namespace Fractrue
 }  // namespace MaterialLib
-
-#endif
diff --git a/MaterialLib/PhysicalConstant.h b/MaterialLib/PhysicalConstant.h
index 60102476de9e6cb3305a4dc1e7e7390f0b842358..cce50a0e92d9a65b234a8ff4038ce0eec58f7c9d 100644
--- a/MaterialLib/PhysicalConstant.h
+++ b/MaterialLib/PhysicalConstant.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef MATERIALSLIB_PHYSICALCONSTANT_H
-#define MATERIALSLIB_PHYSICALCONSTANT_H
+#pragma once
 
 namespace MaterialLib
 {
@@ -89,4 +88,3 @@ const double WaterVapour = IdealGasConstant / MolarMass::Water;  // = 461.504;
 }  // namespace SpecificGasConstant
 }  // namespace PhysicalConstant
 }  // namespace MaterialLib
-#endif  // MATERIALSLIB_PHYSICALCONSTANT_H
diff --git a/MaterialLib/PorousMedium/Permeability/createPermeabilityModel.h b/MaterialLib/PorousMedium/Permeability/createPermeabilityModel.h
index fb408c7ef3889c56e5adc8caca3fa9070bfa5ff2..d7503a845d2731e3a9d60e9a1db230ce6ae98a72 100644
--- a/MaterialLib/PorousMedium/Permeability/createPermeabilityModel.h
+++ b/MaterialLib/PorousMedium/Permeability/createPermeabilityModel.h
@@ -10,8 +10,7 @@
  * Created on August 17, 2016, 2:36 PM
  */
 
-#ifndef OGS_CREATEPERMEABILITYMODEL_H
-#define OGS_CREATEPERMEABILITYMODEL_H
+#pragma once
 
 #include <Eigen/Dense>
 
@@ -31,5 +30,3 @@ Eigen::MatrixXd createPermeabilityModel(BaseLib::ConfigTree const& config);
 
 }  // end of namespace
 }  // end of namespace
-
-#endif /* CREATEPERMEABILITYMODEL_H */
diff --git a/MaterialLib/PorousMedium/Porosity/ConstantPorosity.h b/MaterialLib/PorousMedium/Porosity/ConstantPorosity.h
index 9410199a5bdc7b4763a77b11d6fc3bdebaa88bd1..19a6b02cddc968ec89882e627a6237b024e140dc 100644
--- a/MaterialLib/PorousMedium/Porosity/ConstantPorosity.h
+++ b/MaterialLib/PorousMedium/Porosity/ConstantPorosity.h
@@ -10,8 +10,7 @@
  * Created on August 16, 2016, 1:03 PM
  */
 
-#ifndef OGS_CONSTANTPOROSITY_H
-#define OGS_CONSTANTPOROSITY_H
+#pragma once
 
 #include "Porosity.h"
 
@@ -45,5 +44,3 @@ private:
 
 }  // end of namespace
 }  // end of namespace
-
-#endif /* CONSTANTPOROSITY_H */
diff --git a/MaterialLib/PorousMedium/Porosity/Porosity.h b/MaterialLib/PorousMedium/Porosity/Porosity.h
index 9c21019476912b6f7c0607493cdf0a10af4b8949..a2cf8e3bdc4b5540b4bc41af4ded21772476f67a 100644
--- a/MaterialLib/PorousMedium/Porosity/Porosity.h
+++ b/MaterialLib/PorousMedium/Porosity/Porosity.h
@@ -10,8 +10,7 @@
  * Created on August 16, 2016, 12:53 PM
  */
 
-#ifndef OGS_POROSITY_H
-#define OGS_POROSITY_H
+#pragma once
 
 #include <string>
 
@@ -39,5 +38,3 @@ public:
 
 }  // end of namespace
 }  // end of namespace
-
-#endif /* POROSITY_H */
diff --git a/MaterialLib/PorousMedium/Porosity/createPorosityModel.h b/MaterialLib/PorousMedium/Porosity/createPorosityModel.h
index fd4a3725c4933f18f12dd1121e394d1268549738..8aad3e08036150cc363af11e91a02435a16a7c45 100644
--- a/MaterialLib/PorousMedium/Porosity/createPorosityModel.h
+++ b/MaterialLib/PorousMedium/Porosity/createPorosityModel.h
@@ -10,8 +10,7 @@
  * Created on August 16, 2016, 1:16 PM
  */
 
-#ifndef OGS_CREATEPOROSITYMODEL_H
-#define OGS_CREATEPOROSITYMODEL_H
+#pragma once
 
 #include <memory>
 
@@ -34,5 +33,3 @@ std::unique_ptr<Porosity> createPorosityModel(
 
 }  // end namespace
 }  // end namespace
-
-#endif /* CREATEPOROSITYMODEL_H */
diff --git a/MaterialLib/PorousMedium/PorousPropertyHeaders.h b/MaterialLib/PorousMedium/PorousPropertyHeaders.h
index f816a5c6402c194ce0f56068caf153e522ec79b4..6154b87951480f421f987e74c5422c481ee5adb1 100644
--- a/MaterialLib/PorousMedium/PorousPropertyHeaders.h
+++ b/MaterialLib/PorousMedium/PorousPropertyHeaders.h
@@ -10,11 +10,8 @@
  * Created on August 18, 2016, 11:12 AM
  */
 
-#ifndef OGS_POROUSPROPERTYHEADERS_H
-#define OGS_POROUSPROPERTYHEADERS_H
+#pragma once
 
 #include "Permeability/createPermeabilityModel.h"
 #include "Porosity/createPorosityModel.h"
 #include "Storage/createStorageModel.h"
-
-#endif /* POROUSPROPERTYHEADERS_H */
diff --git a/MaterialLib/PorousMedium/Storage/ConstantStorage.h b/MaterialLib/PorousMedium/Storage/ConstantStorage.h
index 5a5c649e40b9386f5170c0373ed4c97121c56d88..acb5939f326d6a7f553186ad93f031366b5936e9 100644
--- a/MaterialLib/PorousMedium/Storage/ConstantStorage.h
+++ b/MaterialLib/PorousMedium/Storage/ConstantStorage.h
@@ -10,8 +10,7 @@
  * Created on August 16, 2016, 1:03 PM
  */
 
-#ifndef OGS_CONSTANTSTORAGE_H
-#define OGS_CONSTANTSTORAGE_H
+#pragma once
 
 #include "Storage.h"
 
@@ -43,5 +42,3 @@ private:
 
 }  // end of namespace
 }  // end of namespace
-
-#endif /* CONSTANTSTORAGE_H */
diff --git a/MaterialLib/PorousMedium/Storage/Storage.h b/MaterialLib/PorousMedium/Storage/Storage.h
index c06957adf9a9edd15d461b87a0e5fba4d1d2b5d4..dd8d757d49bfb107c40eafd02c9b1f0ae16e7281 100644
--- a/MaterialLib/PorousMedium/Storage/Storage.h
+++ b/MaterialLib/PorousMedium/Storage/Storage.h
@@ -10,8 +10,7 @@
  * Created on August 16, 2016, 12:53 PM
  */
 
-#ifndef OGS_STORAGE_H
-#define OGS_STORAGE_H
+#pragma once
 
 #include <string>
 
@@ -35,5 +34,3 @@ public:
 
 }  // end of namespace
 }  // end of namespace
-
-#endif /* STORAGE_H */
diff --git a/MaterialLib/PorousMedium/Storage/createStorageModel.h b/MaterialLib/PorousMedium/Storage/createStorageModel.h
index 041638ddfa26952aee18a4086d55d790ef0db4bb..ab36494e4211c6ab014e74711414aca1d2b8bcf8 100644
--- a/MaterialLib/PorousMedium/Storage/createStorageModel.h
+++ b/MaterialLib/PorousMedium/Storage/createStorageModel.h
@@ -10,8 +10,7 @@
  * Created on August 16, 2016, 1:16 PM
  */
 
-#ifndef OGS_CREATESTORAGEMODEL_H
-#define OGS_CREATESTORAGEMODEL_H
+#pragma once
 
 #include <memory>
 
@@ -32,5 +31,3 @@ std::unique_ptr<Storage> createStorageModel(BaseLib::ConfigTree const& config);
 
 }  // end namespace
 }  // end namespace
-
-#endif /* CREATESTORAGEMODEL_H */
diff --git a/MaterialLib/PorousMedium/UnsaturatedProperty/CapillaryPressure/BrookCoreyCapillaryPressureSaturation.h b/MaterialLib/PorousMedium/UnsaturatedProperty/CapillaryPressure/BrookCoreyCapillaryPressureSaturation.h
index cd2e8f7482e98917d392a53c61c346ddf9bc28a7..519f2ee1a9687acb4733731b46599ebcbcf22ac4 100644
--- a/MaterialLib/PorousMedium/UnsaturatedProperty/CapillaryPressure/BrookCoreyCapillaryPressureSaturation.h
+++ b/MaterialLib/PorousMedium/UnsaturatedProperty/CapillaryPressure/BrookCoreyCapillaryPressureSaturation.h
@@ -10,8 +10,7 @@
  *  Created on November 1, 2016, 9:45 AM
  */
 
-#ifndef OGS_BROOK_COREY_CAPILLARY_PRESSURE_SATURATION_H
-#define OGS_BROOK_COREY_CAPILLARY_PRESSURE_SATURATION_H
+#pragma once
 
 #include <limits>  // std::numeric_limits
 
@@ -78,4 +77,3 @@ private:
 
 }  // end namespace
 }  // end namespace
-#endif /* OGS_BROOK_COREY_CAPILLARY_PRESSURE_SATURATION_H */
diff --git a/MaterialLib/PorousMedium/UnsaturatedProperty/CapillaryPressure/CapillaryPressureSaturation.h b/MaterialLib/PorousMedium/UnsaturatedProperty/CapillaryPressure/CapillaryPressureSaturation.h
index d5f72af864e7898f0709a9f7d8f58d484c2a6d91..b3dbf9dc6ff58625c19b777316b30ddade7971e9 100644
--- a/MaterialLib/PorousMedium/UnsaturatedProperty/CapillaryPressure/CapillaryPressureSaturation.h
+++ b/MaterialLib/PorousMedium/UnsaturatedProperty/CapillaryPressure/CapillaryPressureSaturation.h
@@ -9,8 +9,7 @@
  *
  */
 
-#ifndef OGS_CAPILLARY_PRESSURE_SATURATION_H
-#define OGS_CAPILLARY_PRESSURE_SATURATION_H
+#pragma once
 
 #include <string>
 
@@ -62,5 +61,3 @@ protected:
 
 }  // end namespace
 }  // end namespace
-
-#endif /* OGS_CAPILLARY_PRESSURE_SATURATION_H */
diff --git a/MaterialLib/PorousMedium/UnsaturatedProperty/CapillaryPressure/CapillaryPressureSaturationCurve.h b/MaterialLib/PorousMedium/UnsaturatedProperty/CapillaryPressure/CapillaryPressureSaturationCurve.h
index 59c9480477e7cc2e5f5af0056efa776df7bd314f..63dc649c1956cf787a4f6647ca35d780e21078c4 100644
--- a/MaterialLib/PorousMedium/UnsaturatedProperty/CapillaryPressure/CapillaryPressureSaturationCurve.h
+++ b/MaterialLib/PorousMedium/UnsaturatedProperty/CapillaryPressure/CapillaryPressureSaturationCurve.h
@@ -10,8 +10,7 @@
  * Created on November 3, 2016, 9:50 AM
  */
 
-#ifndef OGS_CAPILLARY_PRESSURE_SATURATION_CURVE_H
-#define OGS_CAPILLARY_PRESSURE_SATURATION_CURVE_H
+#pragma once
 
 #include <memory>
 
@@ -78,5 +77,3 @@ private:
 
 }  // end namespace
 }  // end namespace
-
-#endif /* OGS_CAPILLARY_PRESSURE_SATURATION_CURVE_H */
diff --git a/MaterialLib/PorousMedium/UnsaturatedProperty/CapillaryPressure/CreateCapillaryPressureModel.h b/MaterialLib/PorousMedium/UnsaturatedProperty/CapillaryPressure/CreateCapillaryPressureModel.h
index bc6b07ba60b3626fd0c918b1f348c536a70a316e..ff2929112f24bf0412687f9e59ff58df38fbf9aa 100644
--- a/MaterialLib/PorousMedium/UnsaturatedProperty/CapillaryPressure/CreateCapillaryPressureModel.h
+++ b/MaterialLib/PorousMedium/UnsaturatedProperty/CapillaryPressure/CreateCapillaryPressureModel.h
@@ -10,8 +10,7 @@
  * Created on November 1, 2016, 10:06 AM
  */
 
-#ifndef OGS_CREATE_CAPILLARY_PRESSURE_MODEL_H
-#define OGS_CREATE_CAPILLARY_PRESSURE_MODEL_H
+#pragma once
 
 #include <memory>
 
@@ -31,5 +30,3 @@ std::unique_ptr<CapillaryPressureSaturation> createCapillaryPressureModel(
     BaseLib::ConfigTree const& config);
 }
 }  // end namespace
-
-#endif /* OGS_CREATE_CAPILLARY_PRESSURE_MODEL_H */
diff --git a/MaterialLib/PorousMedium/UnsaturatedProperty/CapillaryPressure/VanGenuchtenCapillaryPressureSaturation.h b/MaterialLib/PorousMedium/UnsaturatedProperty/CapillaryPressure/VanGenuchtenCapillaryPressureSaturation.h
index 78d02e562aeeeee83f9933e292ed56582f5ad330..3c60b0d1fa42a04c0b8ba2a8824c18870afe5e27 100644
--- a/MaterialLib/PorousMedium/UnsaturatedProperty/CapillaryPressure/VanGenuchtenCapillaryPressureSaturation.h
+++ b/MaterialLib/PorousMedium/UnsaturatedProperty/CapillaryPressure/VanGenuchtenCapillaryPressureSaturation.h
@@ -10,8 +10,7 @@
  *  Created on October 28, 2016, 6:05 PM
  */
 
-#ifndef OGS_VAN_GENUCHTEN_CAPILLARY_PRESSURE_SATURATION_H
-#define OGS_VAN_GENUCHTEN_CAPILLARY_PRESSURE_SATURATION_H
+#pragma once
 
 #include <limits>
 
@@ -83,4 +82,3 @@ private:
 
 }  // end namespace
 }  // end namespace
-#endif /* OGS_VAN_GENUCHTEN_CAPILLARY_PRESSURE_SATURATION_H */
diff --git a/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/CreateRelativePermeabilityModel.h b/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/CreateRelativePermeabilityModel.h
index a93bda565eefff2d088c2d1c03d022b2b4366a41..78d15b53598a2c07af9f9e43264242b8d6b9382e 100644
--- a/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/CreateRelativePermeabilityModel.h
+++ b/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/CreateRelativePermeabilityModel.h
@@ -10,8 +10,7 @@
  * Created on November 2, 2016, 11:43 AM
  */
 
-#ifndef OGS_CREATE_RELATIVE_PERMEABILITY_MODEL_H
-#define OGS_CREATE_RELATIVE_PERMEABILITY_MODEL_H
+#pragma once
 
 #include <memory>
 
@@ -31,5 +30,3 @@ std::unique_ptr<RelativePermeability> createRelativePermeabilityModel(
     BaseLib::ConfigTree const& config);
 }
 }  // end namespace
-
-#endif /* OGS_CREATE_RELATIVE_PERMEABILITY_MODEL_H */
diff --git a/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/NonWettingPhaseBrookCoreyOilGas.h b/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/NonWettingPhaseBrookCoreyOilGas.h
index cc2a2193dfb85b3ed2ee7a19cc3c922d8d0b529c..2361d92a0a5ae104e49d580e869d9de0fe813541 100644
--- a/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/NonWettingPhaseBrookCoreyOilGas.h
+++ b/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/NonWettingPhaseBrookCoreyOilGas.h
@@ -10,8 +10,7 @@
  * Created on November 2, 2016, 10:47 AM
  */
 
-#ifndef OGS_NON_WETTING_PHASE_BROOK_COREY_OIL_GAS_H
-#define OGS_NON_WETTING_PHASE_BROOK_COREY_OIL_GAS_H
+#pragma once
 
 #include "RelativePermeability.h"
 
@@ -73,5 +72,3 @@ private:
 
 }  // end namespace
 }  // end namespace
-
-#endif /* OGS_NON_WETTING_PHASE_BROOK_COREY_OIL_GAS_H */
diff --git a/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/NonWettingPhaseVanGenuchten.h b/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/NonWettingPhaseVanGenuchten.h
index dada1be4732c58009ffeb9c7334ac4a3d039f0a2..88d131cf639a37dac4a5051af85cadc7f327e570 100644
--- a/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/NonWettingPhaseVanGenuchten.h
+++ b/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/NonWettingPhaseVanGenuchten.h
@@ -9,8 +9,7 @@
  *
  * Created on November 2, 2016, 11:24 AM
  */
-#ifndef OGS_NON_WETTING_PHASE_VAN_GENUCHTEN_H
-#define OGS_NON_WETTING_PHASE_VAN_GENUCHTEN_H
+#pragma once
 
 #include "RelativePermeability.h"
 
@@ -75,4 +74,3 @@ private:
 
 }  // end namespace
 }  // end namespace
-#endif /* OGS_NON_WETTING_PHASE_VAN_GENUCHTEN_H */
diff --git a/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/RelativePermeability.h b/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/RelativePermeability.h
index 281b20464260416bb67f20ba308c59283be802bb..31f59b044cae8fc83baa713cccffd959118d43aa 100644
--- a/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/RelativePermeability.h
+++ b/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/RelativePermeability.h
@@ -9,8 +9,7 @@
  *
  */
 
-#ifndef OGS_RELATIVE_PERMEABILITY_H
-#define OGS_RELATIVE_PERMEABILITY_H
+#pragma once
 
 #include <string>
 #include <limits>
@@ -54,5 +53,3 @@ protected:
 
 }  // end namespace
 }  // end namespace
-
-#endif /* OGS_RELATIVE_PERMEABILITY_H */
diff --git a/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/RelativePermeabilityCurve.h b/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/RelativePermeabilityCurve.h
index 09618d288482cf4bf9bd2d4ebf8211dd063d3c23..fa2987ecb6b6b4a67428370900b02911400501a7 100644
--- a/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/RelativePermeabilityCurve.h
+++ b/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/RelativePermeabilityCurve.h
@@ -10,8 +10,7 @@
  * Created on November 2, 2016, 1:41 PM
  */
 
-#ifndef OGS_RELATIVE_PERMEABILITY_CURVE_H
-#define OGS_RELATIVE_PERMEABILITY_CURVE_H
+#pragma once
 
 #include <memory>
 #include "RelativePermeability.h"
@@ -66,4 +65,3 @@ private:
 };
 }  // end namespace
 }  // end namespace
-#endif /* OGS_RELATIVE_PERMEABILITY_CURVE_H */
diff --git a/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/WettingPhaseBrookCoreyOilGas.h b/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/WettingPhaseBrookCoreyOilGas.h
index e5023b0474ae5a250318ecfb4b84b2c750a4265c..30a9e87ce4a0d42976617ead8f9b26202dfe0b2c 100644
--- a/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/WettingPhaseBrookCoreyOilGas.h
+++ b/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/WettingPhaseBrookCoreyOilGas.h
@@ -10,8 +10,7 @@
  * Created on November 1, 2016, 3:37 PM
  */
 
-#ifndef OGS_WETTING_PHASE_BROOK_COREY_OIL_GAS_H
-#define OGS_WETTING_PHASE_BROOK_COREY_OIL_GAS_H
+#pragma once
 
 #include "RelativePermeability.h"
 
@@ -67,4 +66,3 @@ private:
 
 }  // end namespace
 }  // end namespace
-#endif /* OGS_WETTING_PHASE_BROOK_COREY_OIL_GAS_H */
diff --git a/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/WettingPhaseVanGenuchten.h b/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/WettingPhaseVanGenuchten.h
index f501b6bbc21cf5dcc47353bbfdb30831a27b552a..7e0982983cbae35687640ed94e90ffa5781b3b16 100644
--- a/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/WettingPhaseVanGenuchten.h
+++ b/MaterialLib/PorousMedium/UnsaturatedProperty/RelativePermeability/WettingPhaseVanGenuchten.h
@@ -10,8 +10,7 @@
  * Created on November 2, 2016, 11:24 AM
  */
 
-#ifndef OGS_WETTING_PHASE_VAN_GENUCHTEN_H
-#define OGS_WETTING_PHASE_VAN_GENUCHTEN_H
+#pragma once
 
 #include "RelativePermeability.h"
 
@@ -70,4 +69,3 @@ private:
 
 }  // end namespace
 }  // end namespace
-#endif /* OGS_WETTING_PHASE_VAN_GENUCHTEN_H */
diff --git a/MaterialLib/SolidModels/CreateEhlers.h b/MaterialLib/SolidModels/CreateEhlers.h
index 2bc1c17cb995065270f3298b5a31eb9075d7fb34..1f80ef3eac99988a73bc79458e3551e0afb6e870 100644
--- a/MaterialLib/SolidModels/CreateEhlers.h
+++ b/MaterialLib/SolidModels/CreateEhlers.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATERIALLIB_SOLIDMODELS_CREATEEHLERS_H_
-#define MATERIALLIB_SOLIDMODELS_CREATEEHLERS_H_
+#pragma once
 
 #include <logog/include/logog.hpp>
 
@@ -151,5 +150,3 @@ std::unique_ptr<MechanicsBase<DisplacementDim>> createEhlers(
 
 }  // namespace Solids
 }  // namespace MaterialLib
-
-#endif  // MATERIALLIB_SOLIDMODELS_CREATEEHLERS_H_
diff --git a/MaterialLib/SolidModels/CreateLinearElasticIsotropic.h b/MaterialLib/SolidModels/CreateLinearElasticIsotropic.h
index 8518288040ae093cd214e30bd8590c6833ee8179..29110bfa9fa3fc042e3e2cbf844d439385765690 100644
--- a/MaterialLib/SolidModels/CreateLinearElasticIsotropic.h
+++ b/MaterialLib/SolidModels/CreateLinearElasticIsotropic.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATERIALLIB_SOLIDMODELS_CREATELINEARELASTICISOTROPIC_H_
-#define MATERIALLIB_SOLIDMODELS_CREATELINEARELASTICISOTROPIC_H_
+#pragma once
 
 #include "ProcessLib/Utils/ProcessUtils.h"  // required for findParameter
 #include "LinearElasticIsotropic.h"
@@ -51,5 +50,3 @@ createLinearElasticIsotropic(
 
 }  // namespace Solids
 }  // namespace MaterialLib
-
-#endif  // MATERIALLIB_SOLIDMODELS_CREATELINEARELASTICISOTROPIC_H_
diff --git a/MaterialLib/SolidModels/CreateLubby2.h b/MaterialLib/SolidModels/CreateLubby2.h
index b3d76de47d154abb396082e25a907c27e7e3e5ec..0edd11f01817f1391439f0a3e6b00405ca4ee746 100644
--- a/MaterialLib/SolidModels/CreateLubby2.h
+++ b/MaterialLib/SolidModels/CreateLubby2.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATERIALLIB_SOLIDMODELS_CREATELUBBY2_H_
-#define MATERIALLIB_SOLIDMODELS_CREATELUBBY2_H_
+#pragma once
 
 #include <logog/include/logog.hpp>
 
@@ -106,5 +105,3 @@ std::unique_ptr<MechanicsBase<DisplacementDim>> createLubby2(
 
 }  // namespace Solids
 }  // namespace MaterialLib
-
-#endif  // MATERIALLIB_SOLIDMODELS_CREATELUBBY2_H_
diff --git a/MaterialLib/SolidModels/Ehlers-impl.h b/MaterialLib/SolidModels/Ehlers-impl.h
index 8926fce655cd13df8532c51aab083e4c49ab9010..1527e7b6b17940180e1f442f10f93d6becc58b9f 100644
--- a/MaterialLib/SolidModels/Ehlers-impl.h
+++ b/MaterialLib/SolidModels/Ehlers-impl.h
@@ -30,8 +30,7 @@
  * lambda_flow_D    - deviatoric increment of plastic strain
  *
  */
-#ifndef MATERIALLIB_SOLIDMODELS_EHLERS_IMPL_H_
-#define MATERIALLIB_SOLIDMODELS_EHLERS_IMPL_H_
+#pragma once
 
 #include <boost/math/special_functions/pow.hpp>
 #include <logog/include/logog.hpp>
@@ -657,5 +656,3 @@ bool SolidEhlers<DisplacementDim>::computeConstitutiveRelation(
 
 }  // namespace Solids
 }  // namespace MaterialLib
-
-#endif  // MATERIALLIB_SOLIDMODELS_EHLERS_IMPL_H_
diff --git a/MaterialLib/SolidModels/Ehlers.h b/MaterialLib/SolidModels/Ehlers.h
index af640986378e07c96b9cd45c2cfbee9f26acf682..d50a5ff6a15d9ce161298c4e0ac0e663990fa07d 100644
--- a/MaterialLib/SolidModels/Ehlers.h
+++ b/MaterialLib/SolidModels/Ehlers.h
@@ -17,8 +17,7 @@
  * for more details for the tests.
  */
 
-#ifndef MATERIALLIB_SOLIDMODELS_EHLERS_H_
-#define MATERIALLIB_SOLIDMODELS_EHLERS_H_
+#pragma once
 
 #include <cfloat>
 #include <memory>
@@ -211,5 +210,3 @@ private:
 }  // namespace Solids
 }  // namespace MaterialLib
 #include "Ehlers-impl.h"
-
-#endif  // MATERIALLIB_SOLIDMODELS_EHLERS_H_
diff --git a/MaterialLib/SolidModels/KelvinVector.h b/MaterialLib/SolidModels/KelvinVector.h
index d3f7865351abd5bc83cf8241947f68d9df239322..d6253f61ce454fee4f61938f686e690d02034add 100644
--- a/MaterialLib/SolidModels/KelvinVector.h
+++ b/MaterialLib/SolidModels/KelvinVector.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/project/license
  *
  */
-#ifndef MATERIALLIB_SOLIDMODELS_KELVINVECTOR_H
-#define MATERIALLIB_SOLIDMODELS_KELVINVECTOR_H
+#pragma once
 
 #include <Eigen/Dense>
 
@@ -80,5 +79,3 @@ inverse(Eigen::Matrix<double,
 }  // namespace MaterialLib
 
 #include "KelvinVector-impl.h"
-
-#endif  // MATERIALLIB_SOLIDMODELS_KELVINVECTOR_H
diff --git a/MaterialLib/SolidModels/LinearElasticIsotropic.h b/MaterialLib/SolidModels/LinearElasticIsotropic.h
index d66e9ff6d1fd373a622ed978cc4a3adb8b302bbc..3342eb0b4387e186f999df9c3048c7155b250020 100644
--- a/MaterialLib/SolidModels/LinearElasticIsotropic.h
+++ b/MaterialLib/SolidModels/LinearElasticIsotropic.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATERIALLIB_SOLIDMODELS_LINEARELASTICISOTROPIC_H_
-#define MATERIALLIB_SOLIDMODELS_LINEARELASTICISOTROPIC_H_
+#pragma once
 
 #include "MechanicsBase.h"
 
@@ -109,5 +108,3 @@ extern template class LinearElasticIsotropic<3>;
 
 }  // namespace Solids
 }  // namespace MaterialLib
-
-#endif  // MATERIALLIB_SOLIDMODELS_LINEARELASTICISOTROPIC_H_
diff --git a/MaterialLib/SolidModels/Lubby2-impl.h b/MaterialLib/SolidModels/Lubby2-impl.h
index 42a804db341973e95ac09edb924a24132cdd70d7..a52ace4bdcd956d8a6e3519fbf143b1fac0f66e3 100644
--- a/MaterialLib/SolidModels/Lubby2-impl.h
+++ b/MaterialLib/SolidModels/Lubby2-impl.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATERIALLIB_SOLIDMODELS_LUBBY2_IMPL_H_
-#define MATERIALLIB_SOLIDMODELS_LUBBY2_IMPL_H_
+#pragma once
 
 #include "NumLib/NewtonRaphson.h"
 
@@ -267,5 +266,3 @@ void Lubby2<DisplacementDim>::calculateJacobianBurgers(
 
 }  // namespace Solids
 }  // namespace MaterialLib
-
-#endif  // MATERIALLIB_SOLIDMODELS_LUBBY2_IMPL_H_
diff --git a/MaterialLib/SolidModels/Lubby2.h b/MaterialLib/SolidModels/Lubby2.h
index 9ee8ec330fb2cadfa907d4745d12b46abc9304f1..2580349fbe0f264cacd8320cf6e3ba3d5203b6d1 100644
--- a/MaterialLib/SolidModels/Lubby2.h
+++ b/MaterialLib/SolidModels/Lubby2.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATERIALLIB_SOLIDMODELS_LUBBY2_H_
-#define MATERIALLIB_SOLIDMODELS_LUBBY2_H_
+#pragma once
 
 #include <logog/include/logog.hpp>
 
@@ -201,5 +200,3 @@ extern template class Lubby2<3>;
 }  // namespace MaterialLib
 
 #include "Lubby2-impl.h"
-
-#endif  // MATERIALLIB_SOLIDMODELS_LUBBY2_H_
diff --git a/MaterialLib/SolidModels/MechanicsBase.h b/MaterialLib/SolidModels/MechanicsBase.h
index f41050cf9a6851681321c4233c8786eafd5212ac..23292e0f0e8daca128770fa19bf032c3d4ef272d 100644
--- a/MaterialLib/SolidModels/MechanicsBase.h
+++ b/MaterialLib/SolidModels/MechanicsBase.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATERIALLIB_SOLIDMODELS_MECHANICSBASE_H_
-#define MATERIALLIB_SOLIDMODELS_MECHANICSBASE_H_
+#pragma once
 
 #include <memory>
 
@@ -116,5 +115,3 @@ struct MechanicsBase
 
 }  // namespace Solids
 }  // namespace MaterialLib
-
-#endif  // MATERIALLIB_SOLIDMODELS_MECHANICSBASE_H_
diff --git a/MaterialLib/TwoPhaseModels/CreateTwoPhaseFlowMaterialProperties.h b/MaterialLib/TwoPhaseModels/CreateTwoPhaseFlowMaterialProperties.h
index b1af6fe6a4fffe88198a9f496e604bb88e97f8ba..bbf4f4309a9ca284c114c3f2bcbfdc82fe930b5c 100644
--- a/MaterialLib/TwoPhaseModels/CreateTwoPhaseFlowMaterialProperties.h
+++ b/MaterialLib/TwoPhaseModels/CreateTwoPhaseFlowMaterialProperties.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef OGS_CREATETWOPHASEFLOWMATERIALPROPERTIES_H
-#define OGS_CREATETWOPHASEFLOWMATERIALPROPERTIES_H
+#pragma once
 
 #include <memory>
 #include "MaterialLib/Fluid/FluidPropertyHeaders.h"
@@ -33,5 +32,3 @@ CreateTwoPhaseFlowMaterialProperties(
 
 }  // end namespace
 }  // end namespace
-
-#endif /* CREATETWOPHASEFLOWMATERIALPROPERTIES_H */
diff --git a/MaterialLib/TwoPhaseModels/TwoPhaseFlowWithPPMaterialProperties.h b/MaterialLib/TwoPhaseModels/TwoPhaseFlowWithPPMaterialProperties.h
index ba8cba0c15c4bedf7881825baa6027f6775d9790..977cc26e61ceacf88b5a2fbaa9d1d74bdb2ff2de 100644
--- a/MaterialLib/TwoPhaseModels/TwoPhaseFlowWithPPMaterialProperties.h
+++ b/MaterialLib/TwoPhaseModels/TwoPhaseFlowWithPPMaterialProperties.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef OGS_TWOPHASEFLOWWITHPPMATERIALPROPERTIES_H
-#define OGS_TWOPHASEFLOWWITHPPMATERIALPROPERTIES_H
+#pragma once
 
 #include <iostream>
 #include <memory>
@@ -102,4 +101,3 @@ protected:
 
 }  // end of namespace
 }  // end of namespace
-#endif /* TWOPHASEFLOWWITHPPMATERIALPROPERTIES_H */
diff --git a/MathLib/ConstantFunction.h b/MathLib/ConstantFunction.h
index f36bd17e980dfb436b5eda4f357d27e4a0e1a42f..082f4f51c1f7e2312f9592f8353e029443bb7514 100644
--- a/MathLib/ConstantFunction.h
+++ b/MathLib/ConstantFunction.h
@@ -10,8 +10,7 @@
  *
  */
 
-#ifndef MATHLIB_CONSTANTFUNCTION_H_
-#define MATHLIB_CONSTANTFUNCTION_H_
+#pragma once
 
 #include <array>
 #include <numeric>
@@ -42,5 +41,3 @@ private:
 };
 
 }
-
-#endif  // MATHLIB_CONSTANTFUNCTION_H_
diff --git a/MathLib/Curve/CreatePiecewiseLinearCurve.h b/MathLib/Curve/CreatePiecewiseLinearCurve.h
index f4c5d0cec95f41154d728d22b0856a9efdb1a2e5..088139a7e3f9e4bc43e230a2138f48dac80dce34 100644
--- a/MathLib/Curve/CreatePiecewiseLinearCurve.h
+++ b/MathLib/Curve/CreatePiecewiseLinearCurve.h
@@ -10,8 +10,7 @@
  * Created on November 11, 2016, 10:49 AM
  */
 
-#ifndef OGS_CREATE_PIECEWISE_LINEAR_CURVE_H
-#define OGS_CREATE_PIECEWISE_LINEAR_CURVE_H
+#pragma once
 
 #include <memory>
 
@@ -30,5 +29,3 @@ std::unique_ptr<CurveType> createPiecewiseLinearCurve(
 };
 
 #include "CreatePiecewiseLinearCurve-impl.h"
-
-#endif /* OGS_CREATE_PIECEWISE_LINEAR_CURVE_H */
diff --git a/MathLib/Curve/PiecewiseLinearMonotonicCurve.h b/MathLib/Curve/PiecewiseLinearMonotonicCurve.h
index 10a0f8869db666f522eade4dc3f64ff0164cc0fb..b0e5ac7d2614c2c1037fff2e5f7f77b77e729b27 100644
--- a/MathLib/Curve/PiecewiseLinearMonotonicCurve.h
+++ b/MathLib/Curve/PiecewiseLinearMonotonicCurve.h
@@ -10,8 +10,7 @@
  * Created on November 11, 2016, 10:49 AM
  */
 
-#ifndef OGS_PIECE_WISE_LINEAR_MONOTONIC_CURVE_H
-#define OGS_PIECE_WISE_LINEAR_MONOTONIC_CURVE_H
+#pragma once
 
 #include "MathLib/InterpolationAlgorithms/PiecewiseLinearInterpolation.h"
 
@@ -46,4 +45,3 @@ private:
     bool isStrongMonotonic() const;
 };
 }  // namespace
-#endif /* OGS_PIECE_WISE_LINEAR_MONOTONIC_CURVE_H */
diff --git a/MathLib/GeometricBasics.h b/MathLib/GeometricBasics.h
index c4458d26b7ed7de6db09a91cd65ce8ea38eb4221..52d66619b6df356a01ac5dca7bb0bf684ddfef2a 100644
--- a/MathLib/GeometricBasics.h
+++ b/MathLib/GeometricBasics.h
@@ -8,8 +8,7 @@
  *
  */
 
-#ifndef GEOMETRIC_BASICS_H_
-#define GEOMETRIC_BASICS_H_
+#pragma once
 
 #include <cstddef>
 #include <limits>
@@ -179,5 +178,3 @@ bool isCoplanar(const MathLib::Point3d& a, const MathLib::Point3d& b,
                 const MathLib::Point3d& c, const MathLib::Point3d& d);
 
 }  // end namespace MathLib
-
-#endif
diff --git a/MathLib/Integration/GaussLegendre.h b/MathLib/Integration/GaussLegendre.h
index 24b5d8f18eca26f50a9a8ceb52404a798eecf2da..bb81692839f7ff95434a488b9d626a8d76a116c1 100644
--- a/MathLib/Integration/GaussLegendre.h
+++ b/MathLib/Integration/GaussLegendre.h
@@ -10,9 +10,7 @@
  *
  */
 
-
-#ifndef GAUSSLEGENDRE_H_
-#define GAUSSLEGENDRE_H_
+#pragma once
 
 #include "WeightedSum.h"
 
@@ -50,6 +48,3 @@ double const GaussLegendre<4>::W[4];
 #endif
 
 }  // namespace MathLib
-
-#endif // GAUSSLEGENDRE_H_
-
diff --git a/MathLib/Integration/GaussLegendrePyramid.h b/MathLib/Integration/GaussLegendrePyramid.h
index b62b5b54f222c9b9c1bb7138e9eb3decbc105681..980075bf1bd31806f26a0e23fae0cfd27b1728e7 100644
--- a/MathLib/Integration/GaussLegendrePyramid.h
+++ b/MathLib/Integration/GaussLegendrePyramid.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef GAUSSLEGENDREPYRAMID_H_
-#define GAUSSLEGENDREPYRAMID_H_
+#pragma once
 
 #include <array>
 
@@ -51,5 +50,3 @@ template <>
 double const GaussLegendrePyramid<1>::W[1];
 #endif
 }
-
-#endif //GAUSSLEGENDREPYRAMID_H_
diff --git a/MathLib/Integration/GaussLegendreTet.h b/MathLib/Integration/GaussLegendreTet.h
index da09966a0f7dbe76590b785cbe11d2414c8a0ee5..43bf8e69603047c3f2826d84d3e4a1f93258cdc0 100644
--- a/MathLib/Integration/GaussLegendreTet.h
+++ b/MathLib/Integration/GaussLegendreTet.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef GAUSSLEGENDRETET_H_
-#define GAUSSLEGENDRETET_H_
+#pragma once
 
 #include <array>
 
@@ -51,5 +50,3 @@ template <>
 double const GaussLegendreTet<1>::W[1];
 #endif
 }
-
-#endif //GAUSSLEGENDRETET_H_
diff --git a/MathLib/Integration/GaussLegendreTri.h b/MathLib/Integration/GaussLegendreTri.h
index 37d13d524026fb3740bb6dcb1fcd2b008a777a23..55fc4a805cd25bedcec30b764500c1ea36825a28 100644
--- a/MathLib/Integration/GaussLegendreTri.h
+++ b/MathLib/Integration/GaussLegendreTri.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef GAUSSLEGENDRETRI_H_
-#define GAUSSLEGENDRETRI_H_
+#pragma once
 
 #include <array>
 
@@ -56,5 +55,3 @@ template <>
 double const GaussLegendreTri<1>::W[1];
 #endif
 }
-
-#endif //GAUSSLEGENDRETRI_H_
diff --git a/MathLib/Integration/WeightedSum.h b/MathLib/Integration/WeightedSum.h
index c89ad4ffc9f645ad3f11d7effc5da4859c9bfc15..ff8c01bd5e65f62ea9ca07b9c8af4526a94d9444 100644
--- a/MathLib/Integration/WeightedSum.h
+++ b/MathLib/Integration/WeightedSum.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATHLIB_WEIGHTEDSUM_H_
-#define MATHLIB_WEIGHTEDSUM_H_
+#pragma once
 
 namespace MathLib
 {
@@ -63,5 +62,3 @@ struct WeightedSum
 };
 
 }   // namespace MathLib
-
-#endif  // MATHLIB_WEIGHTEDSUM_H_
diff --git a/MathLib/InterpolationAlgorithms/LinearIntervalInterpolation.h b/MathLib/InterpolationAlgorithms/LinearIntervalInterpolation.h
index 0d2f100a112efac94fe7f1b57359434ade0971cc..318e4f0780d6f0e7106799cf9bc8c7f6d8cc13a1 100644
--- a/MathLib/InterpolationAlgorithms/LinearIntervalInterpolation.h
+++ b/MathLib/InterpolationAlgorithms/LinearIntervalInterpolation.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef LINEARINTERVALINTERPOLATION_H_
-#define LINEARINTERVALINTERPOLATION_H_
+#pragma once
 
 #include "BaseLib/Error.h"
 
@@ -79,5 +78,3 @@ inline NUMERIC_TYPE LinearIntervalInterpolation<NUMERIC_TYPE>::operator() (NUMER
 }
 
 } // end namespace MathLib
-
-#endif /* LINEARINTERPOLATION_H_ */
diff --git a/MathLib/InterpolationAlgorithms/PiecewiseLinearInterpolation.h b/MathLib/InterpolationAlgorithms/PiecewiseLinearInterpolation.h
index 7520c4d1852d92bf2ed265bc779cc1212d09c7b2..c9b292ca5489c409f8a4a44d55e7f4d63884ee69 100644
--- a/MathLib/InterpolationAlgorithms/PiecewiseLinearInterpolation.h
+++ b/MathLib/InterpolationAlgorithms/PiecewiseLinearInterpolation.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef PIECEWISELINEARINTERPOLATION_H_
-#define PIECEWISELINEARINTERPOLATION_H_
+#pragma once
 
 #include <vector>
 
@@ -81,5 +80,3 @@ protected:
     std::vector<double> _values_at_supp_pnts;
 };
 }  // end namespace MathLib
-
-#endif /* PIECEWISELINEARINTERPOLATION_H_ */
diff --git a/MathLib/LinAlg/ApplyKnownSolution.h b/MathLib/LinAlg/ApplyKnownSolution.h
index 141970af9ac95bf5bbe6cd11d1cc465f1e3126a0..c8ae2f56f0d91edc88bd0fcf290e7cf90e0b8dd1 100644
--- a/MathLib/LinAlg/ApplyKnownSolution.h
+++ b/MathLib/LinAlg/ApplyKnownSolution.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/LICENSE.txt
  */
 
-#ifndef MATHLIB_APPLYKNOWNSOLUTION_H_
-#define MATHLIB_APPLYKNOWNSOLUTION_H_
+#pragma once
 
 #include <vector>
 
@@ -18,5 +17,3 @@
 #ifdef USE_PETSC
 #include "MathLib/LinAlg/PETSc/PETScTools.h"
 #endif // USE_PETSC
-
-#endif  // MATHLIB_APPLYKNOWNSOLUTION_H_
diff --git a/MathLib/LinAlg/Dense/DenseMatrix.h b/MathLib/LinAlg/Dense/DenseMatrix.h
index b0568e66f975d879a71b819b398200387a6debcc..dd63ba7fdeebae5f820517332e75dce8611d22b9 100644
--- a/MathLib/LinAlg/Dense/DenseMatrix.h
+++ b/MathLib/LinAlg/Dense/DenseMatrix.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef MATRIX_H
-#define MATRIX_H
+#pragma once
 
 #include "MathLib/Vector3.h"
 
@@ -189,5 +188,3 @@ std::ostream& operator<< (std::ostream &os, const DenseMatrix<FP_TYPE, IDX_TYPE>
 } // end namespace MathLib
 
 #include "DenseMatrix-impl.h"
-
-#endif
diff --git a/MathLib/LinAlg/Eigen/EigenLinearSolver.h b/MathLib/LinAlg/Eigen/EigenLinearSolver.h
index d5d42edbee89724f818a7d198506832b543fcdd6..8ecdcc3ff2f3b2c36d53e28a5825279c55a1f6d1 100644
--- a/MathLib/LinAlg/Eigen/EigenLinearSolver.h
+++ b/MathLib/LinAlg/Eigen/EigenLinearSolver.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef EIGENLINEARSOLVER_H_
-#define EIGENLINEARSOLVER_H_
+#pragma once
 
 #include <vector>
 
@@ -62,6 +61,3 @@ protected:
 };
 
 } // MathLib
-
-#endif //EIGENLINEARSOLVER_H_
-
diff --git a/MathLib/LinAlg/Eigen/EigenMapTools.h b/MathLib/LinAlg/Eigen/EigenMapTools.h
index 89a915c849a9a93ffb43b449cad70dfa1dc989ea..cb1a7a8ba54c0e01bfdd72a0fcc239ee2ece4308 100644
--- a/MathLib/LinAlg/Eigen/EigenMapTools.h
+++ b/MathLib/LinAlg/Eigen/EigenMapTools.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATHLIB_EIGENMAPTOOLS_H
-#define MATHLIB_EIGENMAPTOOLS_H
+#pragma once
 
 #include <cassert>
 #include <vector>
@@ -211,5 +210,3 @@ inline Eigen::Map<Eigen::VectorXd> toVector(
 }
 
 }  // MathLib
-
-#endif  // MATHLIB_EIGENMAPTOOLS_H
diff --git a/MathLib/LinAlg/Eigen/EigenMatrix.h b/MathLib/LinAlg/Eigen/EigenMatrix.h
index 07f9cd565c6d77a4ea1157a88d321552f6226f0b..7e0dd62a669b40b07f1e9ccc46a301665b6e2627 100644
--- a/MathLib/LinAlg/Eigen/EigenMatrix.h
+++ b/MathLib/LinAlg/Eigen/EigenMatrix.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef EIGENMATRIX_H_
-#define EIGENMATRIX_H_
+#pragma once
 
 #include <fstream>
 #include <string>
@@ -203,5 +202,3 @@ void operator()(EigenMatrix &matrix, SPARSITY_PATTERN const& sparsity_pattern)
 };
 
 } // end namespace MathLib
-
-#endif
diff --git a/MathLib/LinAlg/Eigen/EigenOption.h b/MathLib/LinAlg/Eigen/EigenOption.h
index 1dd7a599f87c0d294d5f952ec50485bfc6ff7c65..fbf8b4b5467d587e81308e90e8f2607b5fe22ec5 100644
--- a/MathLib/LinAlg/Eigen/EigenOption.h
+++ b/MathLib/LinAlg/Eigen/EigenOption.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef EIGENOPTION_H_
-#define EIGENOPTION_H_
+#pragma once
 
 #include <string>
 
@@ -81,4 +80,3 @@ struct EigenOption final
 };
 
 }
-#endif // EIGENOPTION_H_
diff --git a/MathLib/LinAlg/Eigen/EigenTools.h b/MathLib/LinAlg/Eigen/EigenTools.h
index f88505f07cbe063d941e969e4fccecca39c8d559..acf5960c785cb3a4dc132264a20444cb65c968cd 100644
--- a/MathLib/LinAlg/Eigen/EigenTools.h
+++ b/MathLib/LinAlg/Eigen/EigenTools.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef EIGENTOOLS_H_
-#define EIGENTOOLS_H_
+#pragma once
 
 #include <vector>
 #include <logog/include/logog.hpp>
@@ -46,6 +45,3 @@ void applyKnownSolution(Eigen::MatrixXd &A, Eigen::VectorXd &b, Eigen::VectorXd
 }
 
 } // MathLib
-
-#endif //EIGENTOOLS_H_
-
diff --git a/MathLib/LinAlg/Eigen/EigenVector.h b/MathLib/LinAlg/Eigen/EigenVector.h
index 6e49f0bc3d23949631bdc174a01218fa6e0bfe2a..d5c56e1f606ff7dc5260aab9985e3168b82cb07d 100644
--- a/MathLib/LinAlg/Eigen/EigenVector.h
+++ b/MathLib/LinAlg/Eigen/EigenVector.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef EIGENVECTOR_H_
-#define EIGENVECTOR_H_
+#pragma once
 
 #include <vector>
 #ifndef NDEBUG
@@ -122,6 +121,3 @@ private:
 };
 
 } // MathLib
-
-#endif //EIGENVECTOR_H_
-
diff --git a/MathLib/LinAlg/EigenLis/EigenLisLinearSolver.h b/MathLib/LinAlg/EigenLis/EigenLisLinearSolver.h
index 476bd544b5f5b8de711c097005e3785de1b89811..f5a0551153113bd1b3953f6e17c5645393acd248 100644
--- a/MathLib/LinAlg/EigenLis/EigenLisLinearSolver.h
+++ b/MathLib/LinAlg/EigenLis/EigenLisLinearSolver.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef EIGENLISLINEARSOLVER_H_
-#define EIGENLISLINEARSOLVER_H_
+#pragma once
 
 #include <vector>
 
@@ -52,6 +51,3 @@ private:
 };
 
 } // MathLib
-
-#endif //EIGENLISLINEARSOLVER_H_
-
diff --git a/MathLib/LinAlg/FinalizeMatrixAssembly.h b/MathLib/LinAlg/FinalizeMatrixAssembly.h
index 61ccaf2ce9e7c3baf865743ab2f6e8d946c6dcef..a7ccbe0f618e5a406dcac56909dd422676ec474d 100644
--- a/MathLib/LinAlg/FinalizeMatrixAssembly.h
+++ b/MathLib/LinAlg/FinalizeMatrixAssembly.h
@@ -11,8 +11,7 @@
  *              http://www.opengeosys.org/LICENSE.txt
  */
 
-#ifndef FINALIZEMATRIXASSEMBLY_H_
-#define FINALIZEMATRIXASSEMBLY_H_
+#pragma once
 
 namespace MathLib
 {
@@ -24,5 +23,3 @@ bool finalizeMatrixAssembly(MAT_T &)
 }
 
 } // MathLib
-
-#endif /* FINALIZEMATRIXASSEMBLY_H_ */
diff --git a/MathLib/LinAlg/FinalizeVectorAssembly.h b/MathLib/LinAlg/FinalizeVectorAssembly.h
index 5c85aabfe3287d663e583796a4f258b47ae33692..6c4cec432088e5ae75263b4370b186a8c1030209 100644
--- a/MathLib/LinAlg/FinalizeVectorAssembly.h
+++ b/MathLib/LinAlg/FinalizeVectorAssembly.h
@@ -11,8 +11,7 @@
  *
  */
 
-#ifndef FINALIZEVECTORASSEMBLY_H_
-#define FINALIZEVECTORASSEMBLY_H_
+#pragma once
 
 namespace MathLib
 {
@@ -23,5 +22,3 @@ void finalizeVectorAssembly(VEC_T &)
 }
 
 } // MathLib
-
-#endif
diff --git a/MathLib/LinAlg/GlobalMatrixVectorTypes.h b/MathLib/LinAlg/GlobalMatrixVectorTypes.h
index 28b7946bdec1286445a65d952545356bc241312a..e8cc51832bf9221c674276707540cb377967690e 100644
--- a/MathLib/LinAlg/GlobalMatrixVectorTypes.h
+++ b/MathLib/LinAlg/GlobalMatrixVectorTypes.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATHLIB_LINALG_GLOBALMATRIXVECTORTYPES_H
-#define MATHLIB_LINALG_GLOBALMATRIXVECTORTYPES_H
+#pragma once
 
 #include "SparsityPattern.h"
 
@@ -62,5 +61,3 @@ static_assert(std::is_same<GlobalMatrix::IndexType,
 using GlobalIndexType = GlobalMatrix::IndexType;
 
 using GlobalSparsityPattern = MathLib::SparsityPattern<GlobalIndexType>;
-
-#endif // MATHLIB_LINALG_GLOBALMATRIXVECTORTYPES_H
diff --git a/MathLib/LinAlg/LinAlg.h b/MathLib/LinAlg/LinAlg.h
index 823bcda1ba258b67701445247c2b7d5b4f4e0394..06388524bce6be8f241a152211a724c502cb9678 100644
--- a/MathLib/LinAlg/LinAlg.h
+++ b/MathLib/LinAlg/LinAlg.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATHLIB_LINALG_H
-#define MATHLIB_LINALG_H
+#pragma once
 
 #include <cassert>
 #include "BaseLib/Error.h"
@@ -253,5 +252,3 @@ void finalizeAssembly(EigenMatrix& A);
 } // namespace MathLib
 
 #endif
-
-#endif // MATHLIB_LINALG_H
diff --git a/MathLib/LinAlg/LinAlgEnums.h b/MathLib/LinAlg/LinAlgEnums.h
index cd40fad8272b9e1b094af37654d03256ade89103..c63992c30e1b42dc1476cd136fb9da7c07a7225a 100644
--- a/MathLib/LinAlg/LinAlgEnums.h
+++ b/MathLib/LinAlg/LinAlgEnums.h
@@ -9,8 +9,7 @@
  *
  */
 
-#ifndef LINALGENUMS_H_
-#define LINALGENUMS_H_
+#pragma once
 
 #include <string>
 
@@ -33,5 +32,3 @@ std::string convertVecNormTypeToString(VecNormType normType);
 VecNormType convertStringToVecNormType(const std::string &str);
 
 } // end namespace MathLib
-
-#endif /* LINALGENUMS_H_ */
diff --git a/MathLib/LinAlg/LinearSolverOptions.h b/MathLib/LinAlg/LinearSolverOptions.h
index 7fb07b42a7b74093a7e792c3a93a15a6194fd44a..d15f4627d38d4f4382a2d2fb2f337efe1d0e593c 100644
--- a/MathLib/LinAlg/LinearSolverOptions.h
+++ b/MathLib/LinAlg/LinearSolverOptions.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATHLIB_LINEAR_SOLVER_OPTIONS_H
-#define MATHLIB_LINEAR_SOLVER_OPTIONS_H
+#pragma once
 
 #include "BaseLib/ConfigTree.h"
 
@@ -37,5 +36,3 @@ void ignoreOtherLinearSolvers(BaseLib::ConfigTree const& config,
                               std::string const& solver_name);
 
 }
-
-#endif
diff --git a/MathLib/LinAlg/Lis/LisCheck.h b/MathLib/LinAlg/Lis/LisCheck.h
index 744f1a66d6ac3aa29b9022dcd40a7766baf5db46..1def988c422fe5f21b22bfd052dd6a405b4da1e4 100644
--- a/MathLib/LinAlg/Lis/LisCheck.h
+++ b/MathLib/LinAlg/Lis/LisCheck.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef LISCHECK_H_
-#define LISCHECK_H_
+#pragma once
 
 #include <vector>
 #include "lis.h"
@@ -38,6 +37,3 @@ inline bool checkLisError(int err)
 }
 
 } // MathLib
-
-#endif //LISCHECK_H_
-
diff --git a/MathLib/LinAlg/Lis/LisLinearSolver.h b/MathLib/LinAlg/Lis/LisLinearSolver.h
index 740937e84f031c958d99ae191621f466dd8d559a..f5801a40233f2cf2f9777a323146fc2ad2506c38 100644
--- a/MathLib/LinAlg/Lis/LisLinearSolver.h
+++ b/MathLib/LinAlg/Lis/LisLinearSolver.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef LISLINEARSOLVER_H_
-#define LISLINEARSOLVER_H_
+#pragma once
 
 #include <vector>
 #include <string>
@@ -61,6 +60,3 @@ private:
 };
 
 } // MathLib
-
-#endif //LISLINEARSOLVER_H_
-
diff --git a/MathLib/LinAlg/Lis/LisMatrix.h b/MathLib/LinAlg/Lis/LisMatrix.h
index c2e4d0d36de84d8cede91d493d9bfa515d4aa49c..05b7042a3524e246de5e6f3848008c19f55f235d 100644
--- a/MathLib/LinAlg/Lis/LisMatrix.h
+++ b/MathLib/LinAlg/Lis/LisMatrix.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef LISMATRIX_H_
-#define LISMATRIX_H_
+#pragma once
 
 #include <string>
 #include <vector>
@@ -207,5 +206,3 @@ void operator()(LisMatrix &matrix, SPARSITY_PATTERN const& sparsity_pattern)
 
 
 } // MathLib
-
-#endif //LISMATRIX_H_
diff --git a/MathLib/LinAlg/Lis/LisOption.h b/MathLib/LinAlg/Lis/LisOption.h
index eefad7b20851ef711f27b30c96b972c995cf7545..c669db7874c6d6b6aa8508ec0a7494f0630676cf 100644
--- a/MathLib/LinAlg/Lis/LisOption.h
+++ b/MathLib/LinAlg/Lis/LisOption.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef LIS_OPTION_H_
-#define LIS_OPTION_H_
+#pragma once
 
 #include <string>
 #include <map>
@@ -58,4 +57,3 @@ struct LisOption
 
 };
 }
-#endif  // LIS_OPTION_H_
diff --git a/MathLib/LinAlg/Lis/LisVector.h b/MathLib/LinAlg/Lis/LisVector.h
index 27b7a6b4738b6f56206a9fb91c56bd3633563291..12b52d00c19acaf418e5ede78c8ecdd9e35db84a 100644
--- a/MathLib/LinAlg/Lis/LisVector.h
+++ b/MathLib/LinAlg/Lis/LisVector.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef LISVECTOR_H_
-#define LISVECTOR_H_
+#pragma once
 
 #include <string>
 #include <vector>
@@ -112,5 +111,3 @@ private:
 };
 
 }  // MathLib
-
-#endif  // LISVECTOR_H_
diff --git a/MathLib/LinAlg/MatrixSpecifications.h b/MathLib/LinAlg/MatrixSpecifications.h
index 9722b2e13833a758740744a9a8c489fb7696427c..4e5f01add20a200dcb2f71dd07bb6f607e5e538e 100644
--- a/MathLib/LinAlg/MatrixSpecifications.h
+++ b/MathLib/LinAlg/MatrixSpecifications.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATHLIB_LINALG_MATRIXSPECIFICATIONS_H
-#define MATHLIB_LINALG_MATRIXSPECIFICATIONS_H
+#pragma once
 
 #include "GlobalMatrixVectorTypes.h"
 
@@ -32,6 +31,3 @@ struct MatrixSpecifications
 };
 
 } // namespace MathLib
-
-
-#endif // MATHLIB_LINALG_MATRIXSPECIFICATIONS_H
diff --git a/MathLib/LinAlg/MatrixVectorTraits.h b/MathLib/LinAlg/MatrixVectorTraits.h
index 464fe9da5c1c5860df99a912f09e3ffd4a729217..2dd95190cc69a78e8fb6eaab267b8734d1bcfa6b 100644
--- a/MathLib/LinAlg/MatrixVectorTraits.h
+++ b/MathLib/LinAlg/MatrixVectorTraits.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATHLIB_MATRIX_VECTOR_TRAITS_H
-#define MATHLIB_MATRIX_VECTOR_TRAITS_H
+#pragma once
 
 #include <memory>
 #include "MatrixSpecifications.h"
@@ -54,5 +53,3 @@ SPECIALIZE_MATRIX_VECTOR_TRAITS(EigenVector, EigenVector::IndexType)
 #endif
 
 #undef SPECIALIZE_MATRIX_VECTOR_TRAITS
-
-#endif // MATHLIB_MATRIX_VECTOR_TRAITS_H
diff --git a/MathLib/LinAlg/PETSc/PETScLinearSolver.h b/MathLib/LinAlg/PETSc/PETScLinearSolver.h
index b9dd1abc43d2c858572a730f01d4c3083a8e8858..d3c69583775aef946377df8abe3a5f4ac04c6d01 100644
--- a/MathLib/LinAlg/PETSc/PETScLinearSolver.h
+++ b/MathLib/LinAlg/PETSc/PETScLinearSolver.h
@@ -14,8 +14,7 @@
                http://www.opengeosys.org/project/license
 */
 
-#ifndef PETSCLINEARSOLVER_H_
-#define PETSCLINEARSOLVER_H_
+#pragma once
 
 #include<string>
 
@@ -83,5 +82,3 @@ class PETScLinearSolver
 };
 
 } // end namespace
-#endif
-
diff --git a/MathLib/LinAlg/PETSc/PETScMatrix.h b/MathLib/LinAlg/PETSc/PETScMatrix.h
index 34f01030676815e82c3bc67abf58019a95a37c90..50b623fa3d18ff8fffda6c0f98c9ed7054521ff1 100644
--- a/MathLib/LinAlg/PETSc/PETScMatrix.h
+++ b/MathLib/LinAlg/PETSc/PETScMatrix.h
@@ -12,8 +12,7 @@
                See accompanying file LICENSE.txt or
                http://www.opengeosys.org/project/license
 */
-#ifndef PETSCMATRIX_H_
-#define PETSCMATRIX_H_
+#pragma once
 
 #include <string>
 #include <vector>
@@ -287,5 +286,3 @@ void PETScMatrix::add(std::vector<PetscInt> const& row_pos,
 bool finalizeMatrixAssembly(PETScMatrix &mat, const MatAssemblyType asm_type = MAT_FINAL_ASSEMBLY);
 
 } // end namespace
-#endif
-
diff --git a/MathLib/LinAlg/PETSc/PETScMatrixOption.h b/MathLib/LinAlg/PETSc/PETScMatrixOption.h
index 72c10c72d609f8324d3c4bfd1352e2a1d2bcce53..66a6750cc4c25b82f0bbdece319e003324810f76 100644
--- a/MathLib/LinAlg/PETSc/PETScMatrixOption.h
+++ b/MathLib/LinAlg/PETSc/PETScMatrixOption.h
@@ -11,8 +11,7 @@
                See accompanying file LICENSE.txt or
                http://www.opengeosys.org/project/license
 */
-#ifndef PETSCMATRIXOPTION_H_
-#define PETSCMATRIXOPTION_H_
+#pragma once
 
 #include <petscmat.h>
 
@@ -53,5 +52,3 @@ struct PETScMatrixOption
 };
 
 } // end namespace
-#endif
-
diff --git a/MathLib/LinAlg/PETSc/PETScTools.h b/MathLib/LinAlg/PETSc/PETScTools.h
index fe771e9b23f9378edc8b154dc14aad99513e42dc..9c0a20db04a95b090ac107053bee626bb401045e 100644
--- a/MathLib/LinAlg/PETSc/PETScTools.h
+++ b/MathLib/LinAlg/PETSc/PETScTools.h
@@ -14,8 +14,7 @@
                http://www.opengeosys.org/project/license
 */
 
-#ifndef PETSCTOOLS_H_
-#define PETSCTOOLS_H_
+#pragma once
 
 #include <vector>
 
@@ -37,6 +36,3 @@ void applyKnownSolution(PETScMatrix &A, PETScVector &b, PETScVector &x,
                         const std::vector<PetscInt> &vec_knownX_id,
                         const std::vector<PetscScalar> &vec_knownX_x);
 } // end of namespace MathLib
-
-#endif //end  of PETSCTOOLS_H_
-
diff --git a/MathLib/LinAlg/PETSc/PETScVector.h b/MathLib/LinAlg/PETSc/PETScVector.h
index befe4c014aff30aa715c828d10b0585d38b03b6f..cba4692313e73cdc099c0d9cfa1e2048e182c27a 100644
--- a/MathLib/LinAlg/PETSc/PETScVector.h
+++ b/MathLib/LinAlg/PETSc/PETScVector.h
@@ -14,8 +14,7 @@
  *
  */
 
-#ifndef PETSCVECTOR_H_
-#define PETSCVECTOR_H_
+#pragma once
 
 #include <string>
 #include <vector>
@@ -301,4 +300,3 @@ class PETScVector
 void finalizeVectorAssembly(PETScVector &vec);
 
 } // end namespace
-#endif
diff --git a/MathLib/LinAlg/RowColumnIndices.h b/MathLib/LinAlg/RowColumnIndices.h
index 0bd03719c6153b6b3933d621025c5b894f132b48..f75587cf00aca801978fd01e8532f289983a19b1 100644
--- a/MathLib/LinAlg/RowColumnIndices.h
+++ b/MathLib/LinAlg/RowColumnIndices.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef ROWCOLUMNINDICES_H_
-#define ROWCOLUMNINDICES_H_
+#pragma once
 
 #include <vector>
 
@@ -28,5 +27,3 @@ struct RowColumnIndices
 };
 
 } // MathLib
-
-#endif  // ROWCOLUMNINDICES_H_
diff --git a/MathLib/LinAlg/SetMatrixSparsity.h b/MathLib/LinAlg/SetMatrixSparsity.h
index fe6dd7f360bf8c65a47626ddd3df6383ed4ce402..cc9bf655f876111935c1324096854e3cd0dd7ac1 100644
--- a/MathLib/LinAlg/SetMatrixSparsity.h
+++ b/MathLib/LinAlg/SetMatrixSparsity.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/LICENSE.txt
  */
 
-#ifndef MATHLIB_SETMATRIXSPARSITY_H_
-#define MATHLIB_SETMATRIXSPARSITY_H_
+#pragma once
 
 namespace MathLib
 {
@@ -41,5 +40,3 @@ void setMatrixSparsity(MATRIX& matrix, SPARSITY_PATTERN const& sparsity_pattern)
 #ifdef OGS_USE_EIGEN
 #include "Eigen/EigenMatrix.h"
 #endif  // OGS_USE_EIGEN
-
-#endif  // MATHLIB_SETMATRIXSPARSITY_H_
diff --git a/MathLib/LinAlg/Solvers/GaussAlgorithm.h b/MathLib/LinAlg/Solvers/GaussAlgorithm.h
index e8b14c53588b6b2e2a6f21a40c4d8fc15101018d..dbe67099badcee8ebffdd1e8f88e659bdaf8f34e 100644
--- a/MathLib/LinAlg/Solvers/GaussAlgorithm.h
+++ b/MathLib/LinAlg/Solvers/GaussAlgorithm.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef GAUSSALGORITHM_H_
-#define GAUSSALGORITHM_H_
+#pragma once
 
 #include <vector>
 
@@ -100,5 +99,3 @@ private:
 } // end namespace MathLib
 
 #include "GaussAlgorithm-impl.h"
-
-#endif /* GAUSSALGORITHM_H_ */
diff --git a/MathLib/LinAlg/Solvers/TriangularSolve.h b/MathLib/LinAlg/Solvers/TriangularSolve.h
index f358c4258b498da0de2cfb477381d525e84ebfe2..51543ce397fc84a67ebda53f28b5e3ffd944c20b 100644
--- a/MathLib/LinAlg/Solvers/TriangularSolve.h
+++ b/MathLib/LinAlg/Solvers/TriangularSolve.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef TRIANGULARSOLVE_H_
-#define TRIANGULARSOLVE_H_
+#pragma once
 
 #include "../Dense/DenseMatrix.h"
 
@@ -51,5 +50,3 @@ void backwardSolve ( DenseMatrix<FP_T> const& mat, VEC_T& x, VEC_T const& b);
 } // end namespace MathLib
 
 #include "TriangularSolve-impl.h"
-
-#endif /* TRIANGULARSOLVE_H_ */
diff --git a/MathLib/LinAlg/SparsityPattern.h b/MathLib/LinAlg/SparsityPattern.h
index 64f2328529690e7e2877342b8c1d6759fd635d7a..92089345dc6c6b10b1ffd0cf46b2a36054f24f90 100644
--- a/MathLib/LinAlg/SparsityPattern.h
+++ b/MathLib/LinAlg/SparsityPattern.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATHLIB_LINALG_SPARSITYPATTERN_H
-#define MATHLIB_LINALG_SPARSITYPATTERN_H
+#pragma once
 
 #include <vector>
 
@@ -18,5 +17,3 @@ namespace MathLib
 template <typename IndexType>
 using SparsityPattern = std::vector<IndexType>;
 }
-
-#endif // MATHLIB_LINALG_SPARSITYPATTERN_H
diff --git a/MathLib/LinAlg/UnifiedMatrixSetters.h b/MathLib/LinAlg/UnifiedMatrixSetters.h
index 2afcd8e4d00e91d0c8f217d29b57aa47552a2c70..7ee46580129f6f171bf67f41eb46e7224dd2056f 100644
--- a/MathLib/LinAlg/UnifiedMatrixSetters.h
+++ b/MathLib/LinAlg/UnifiedMatrixSetters.h
@@ -9,8 +9,7 @@
 
 // TODO merge that with MatrixVectorTraits?
 
-#ifndef MATHLIB_UNIFIED_MATRIX_SETTERS_H
-#define MATHLIB_UNIFIED_MATRIX_SETTERS_H
+#pragma once
 
 #include <initializer_list>
 #include <Eigen/Core>
@@ -69,5 +68,3 @@ void addToMatrix(EigenMatrix& m,
 } // namespace MathLib
 
 #endif // OGS_USE_EIGEN
-
-#endif // MATHLIB_UNIFIED_MATRIX_SETTERS_H
diff --git a/MathLib/LinearFunction.h b/MathLib/LinearFunction.h
index 402b072f0db7f1c43181d213505f52ab5917fba8..1d5b593fc2096bae5109e7eded4d8b0590443e60 100644
--- a/MathLib/LinearFunction.h
+++ b/MathLib/LinearFunction.h
@@ -10,8 +10,7 @@
  *
  */
 
-#ifndef LINEARFUNCTION_H_
-#define LINEARFUNCTION_H_
+#pragma once
 
 #include <array>
 #include <numeric>
@@ -56,5 +55,3 @@ private:
 };
 
 } // MathLib
-
-#endif /* LINEARFUNCTION_H_ */
diff --git a/MathLib/MathTools.h b/MathLib/MathTools.h
index bb074813801516ae2cae70437754db410d8200ea..627854e7939ef172bcaa0b75a49f22f12a202327 100644
--- a/MathLib/MathTools.h
+++ b/MathLib/MathTools.h
@@ -8,8 +8,7 @@
  *
  */
 
-#ifndef MATHTOOLS_H_
-#define MATHTOOLS_H_
+#pragma once
 
 #include <cstddef>
 
@@ -131,5 +130,3 @@ template<typename Type> Type limitValueInInterval(const Type variable,
     return variable;
 }
 } // namespace
-
-#endif /* MATHTOOLS_H_ */
diff --git a/MathLib/Nonlinear/Root1D.h b/MathLib/Nonlinear/Root1D.h
index 53a2d1449d6babc4ac920b5c42b2e6e4af54d4bc..7b60212e87527eb5accf5e92b5b061598401334e 100644
--- a/MathLib/Nonlinear/Root1D.h
+++ b/MathLib/Nonlinear/Root1D.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATHLIB_NONLINEAR_ROOT1D_H
-#define MATHLIB_NONLINEAR_ROOT1D_H
+#pragma once
 
 #include <cassert>
 #include <cmath>
@@ -161,5 +160,3 @@ struct AndersonBjorck
 }
 
 } // namespace MathLib
-
-#endif // MATHLIB_NONLINEAR_ROOT1D_H
diff --git a/MathLib/ODE/CVodeSolver.h b/MathLib/ODE/CVodeSolver.h
index a7ecd364bb1e1a0e9142f3210759ef013f2c3701..7bb43b1b3f01a27e97f3f6fa704264add69c8296 100644
--- a/MathLib/ODE/CVodeSolver.h
+++ b/MathLib/ODE/CVodeSolver.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATHLIB_CVODESOLVER_H
-#define MATHLIB_CVODESOLVER_H
+#pragma once
 
 #include <memory>
 
@@ -77,5 +76,3 @@ private:
 
 }  // namespace ODE
 }  // namespace MathLib
-
-#endif  // MATHLIB_CVODESOLVER_H
diff --git a/MathLib/ODE/ConcreteODESolver.h b/MathLib/ODE/ConcreteODESolver.h
index 8ac107be7a4c73f734b1637d0f244248b96d7acb..ae688d88b2e4b14c69b57cb8876a7179a6a55ef1 100644
--- a/MathLib/ODE/ConcreteODESolver.h
+++ b/MathLib/ODE/ConcreteODESolver.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATHLIB_ODE_CONCRETEODESOLVER_H
-#define MATHLIB_ODE_CONCRETEODESOLVER_H
+#pragma once
 
 #include <memory>
 
@@ -119,5 +118,3 @@ private:
 
 }  // namespace ODE
 }  // namespace MathLib
-
-#endif  // MATHLIB_ODE_CONCRETEODESOLVER_H
diff --git a/MathLib/ODE/FunctionHandles.h b/MathLib/ODE/FunctionHandles.h
index 4eae69697d689dd4b70312da8568d6ab7b014637..b4df79f6c862ad3019f62ddeac548f6fd17f873a 100644
--- a/MathLib/ODE/FunctionHandles.h
+++ b/MathLib/ODE/FunctionHandles.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATHLIB_ODE_HANDLES_H
-#define MATHLIB_ODE_HANDLES_H
+#pragma once
 
 #include "ODESolverTypes.h"
 
@@ -111,5 +110,3 @@ struct FunctionHandlesImpl final : public FunctionHandles
 }  // namespace detail
 }  // namespace ODE
 }  // namespace MathLib
-
-#endif  // MATHLIB_ODE_HANDLES_H
diff --git a/MathLib/ODE/ODESolver.h b/MathLib/ODE/ODESolver.h
index d651ce6c25af92e41a592088c9811cc1786f5acf..463ab373889f3992a467edebad2cdec0de5ba5c3 100644
--- a/MathLib/ODE/ODESolver.h
+++ b/MathLib/ODE/ODESolver.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATHLIB_ODESOLVER_H
-#define MATHLIB_ODESOLVER_H
+#pragma once
 
 #include <array>
 
@@ -136,5 +135,3 @@ public:
 
 }  // namespace ODE
 }  // namespace MathLib
-
-#endif  // MATHLIB_ODESOLVER_H
diff --git a/MathLib/ODE/ODESolverBuilder.h b/MathLib/ODE/ODESolverBuilder.h
index 62b2813384d38ae329c9ffc0b77233e56cc003ba..04b9078ef03e666373d154c3769537715cf04e78 100644
--- a/MathLib/ODE/ODESolverBuilder.h
+++ b/MathLib/ODE/ODESolverBuilder.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATHLIB_ODE_ODESOLVERBUILDER_H
-#define MATHLIB_ODE_ODESOLVERBUILDER_H
+#pragma once
 
 #include <logog/include/logog.hpp>
 
@@ -55,5 +54,3 @@ std::unique_ptr<ODESolver<NumEquations>> createODESolver(
 
 }  // namespace ODE
 }  // namespace MathLib
-
-#endif  // MATHLIB_ODE_ODESOLVERBUILDER_H
diff --git a/MathLib/ODE/ODESolverTypes.h b/MathLib/ODE/ODESolverTypes.h
index 84e426b43530ef61c6ff246bdfa4daf2e2a4c6b9..487bbbf6f47c6f9140a68cae21cce5a113e43c02 100644
--- a/MathLib/ODE/ODESolverTypes.h
+++ b/MathLib/ODE/ODESolverTypes.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MATHLIB_ODE_ODESOLVERTYPES_H
-#define MATHLIB_ODE_ODESOLVERTYPES_H
+#pragma once
 
 #include <functional>
 #include <Eigen/Core>
@@ -70,5 +69,3 @@ using JacobianFunction = std::function<bool(const double t,
 
 }  // namespace ODE
 }  // namespace MathLib
-
-#endif  // MATHLIB_ODE_ODESOLVERTYPES_H
diff --git a/MathLib/Point3d.h b/MathLib/Point3d.h
index e218c6c90b74e044fb8bbc4e104a91bf8ec8373c..f8a4cda77e258304c1d361cc067c28f10b08ecff 100644
--- a/MathLib/Point3d.h
+++ b/MathLib/Point3d.h
@@ -11,8 +11,7 @@
  *
  */
 
-#ifndef POINT3D_H_
-#define POINT3D_H_
+#pragma once
 
 #include <limits>
 
@@ -60,6 +59,3 @@ double sqrDist2d(MathLib::Point3d const& p0, MathLib::Point3d const& p1)
 }
 
 } // end namespace MathLib
-
-#endif /* POINT3D_H_ */
-
diff --git a/MathLib/Point3dWithID.h b/MathLib/Point3dWithID.h
index a8b8c0a50214b01a2febf8d3ec199710455d63c0..8a9cc335421c61ca352738026b3e3bd1b039413c 100644
--- a/MathLib/Point3dWithID.h
+++ b/MathLib/Point3dWithID.h
@@ -11,8 +11,7 @@
  *
  */
 
-#ifndef POINT3DWITHID_H_
-#define POINT3DWITHID_H_
+#pragma once
 
 #include <limits>
 
@@ -68,6 +67,3 @@ protected:
 };
 
 }
-
-#endif /* POINT3DWITHID_H_ */
-
diff --git a/MathLib/TemplatePoint.h b/MathLib/TemplatePoint.h
index 5e16c18a16abd811eaa81906accaa7694e318036..92bc97d107f69c413a7b107536bd17fa14ed226c 100644
--- a/MathLib/TemplatePoint.h
+++ b/MathLib/TemplatePoint.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef TEMPLATEPOINT_H_
-#define TEMPLATEPOINT_H_
+#pragma once
 
 // STL
 #include <array>
@@ -199,5 +198,3 @@ std::istream& operator>> (std::istream &is, TemplatePoint<T,DIM> &p)
     return is;
 }
 } // end namespace MathLib
-
-#endif /* TEMPLATEPOINT_H_ */
diff --git a/MathLib/TemplateWeightedPoint.h b/MathLib/TemplateWeightedPoint.h
index 351754e8faa1ba28174a81079a106f44a4be0467..318566c198041f6e651aa803b8bd1eba28f94d5d 100644
--- a/MathLib/TemplateWeightedPoint.h
+++ b/MathLib/TemplateWeightedPoint.h
@@ -10,8 +10,7 @@
  *              http://www.opengeosys.org/LICENSE.txt
  */
 
-#ifndef TEMPLATEWEIGHTEDPOINT_H_
-#define TEMPLATEWEIGHTEDPOINT_H_
+#pragma once
 
 #include "TemplatePoint.h"
 
@@ -40,6 +39,3 @@ typedef TemplateWeightedPoint<double, double, 2> WeightedPoint2D;
 typedef TemplateWeightedPoint<double, double, 3> WeightedPoint3D;
 
 } // end namespace MathLib
-
-
-#endif /* TEMPLATEWEIGHTEDPOINT_H_ */
diff --git a/MathLib/Vector3.h b/MathLib/Vector3.h
index af1d1d4362b4cbde338e22994e387656814bdd4f..e880b55a6a611471f916a481ef46384b4ba98e63 100644
--- a/MathLib/Vector3.h
+++ b/MathLib/Vector3.h
@@ -14,8 +14,7 @@
  *
  */
 
-#ifndef VECTOR3_H
-#define VECTOR3_H
+#pragma once
 
 #include <cmath>
 
@@ -193,5 +192,3 @@ double scalarTriple(MathLib::Vector3 const& u, MathLib::Vector3 const& v,
                     MathLib::Vector3 const& w);
 
 }
-
-#endif // VECTOR3_H
diff --git a/MeshGeoToolsLib/AppendLinesAlongPolyline.h b/MeshGeoToolsLib/AppendLinesAlongPolyline.h
index 828f98b316495e280594f3f0977ed5f5c0e94e67..0940c886af3ae0e0fd550aea07dd82d038116062 100644
--- a/MeshGeoToolsLib/AppendLinesAlongPolyline.h
+++ b/MeshGeoToolsLib/AppendLinesAlongPolyline.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/LICENSE.txt
  */
 
-#ifndef APPENDLINESALONGPOLYLINES_H_
-#define APPENDLINESALONGPOLYLINES_H_
+#pragma once
 
 #include <memory>
 
@@ -42,5 +41,3 @@ namespace MeshGeoToolsLib
 std::unique_ptr<MeshLib::Mesh> appendLinesAlongPolylines(
     const MeshLib::Mesh& mesh, const GeoLib::PolylineVec& ply_vec);
 }
-
-#endif
diff --git a/MeshGeoToolsLib/BoundaryElementsAlongPolyline.h b/MeshGeoToolsLib/BoundaryElementsAlongPolyline.h
index 355937494e1706c0b1d0865c15868fc853edf2c0..677efacccab8b4392054ecb4ed7463121bbfc57f 100644
--- a/MeshGeoToolsLib/BoundaryElementsAlongPolyline.h
+++ b/MeshGeoToolsLib/BoundaryElementsAlongPolyline.h
@@ -5,8 +5,7 @@
  *              See accompanying file LICENSE.txt or
  *              http://www.opengeosys.org/LICENSE.txt
  */
-#ifndef BOUNDARYELEMENTSALONGPOLYLINE_H_
-#define BOUNDARYELEMENTSALONGPOLYLINE_H_
+#pragma once
 
 #include <vector>
 
@@ -85,5 +84,3 @@ private:
 };
 
 } // end namespace MeshGeoToolsLib
-
-#endif /* BOUNDARYELEMENTSALONGPOLYLINE_H_ */
diff --git a/MeshGeoToolsLib/BoundaryElementsAtPoint.h b/MeshGeoToolsLib/BoundaryElementsAtPoint.h
index 770108725725142ebdad8c1b6e182e0d9c13c24b..9e4b843bdedd53df175700c2e34afc7d9d6503da 100644
--- a/MeshGeoToolsLib/BoundaryElementsAtPoint.h
+++ b/MeshGeoToolsLib/BoundaryElementsAtPoint.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/LICENSE.txt
  */
 
-#ifndef BOUNDARYELEMENTSATPOINT_H_
-#define BOUNDARYELEMENTSATPOINT_H_
+#pragma once
 
 #include <vector>
 
@@ -64,5 +63,3 @@ private:
 };
 
 }  // end namespace MeshGeoToolsLib
-
-#endif  // BOUNDARYELEMENTSATPOINT_H_
diff --git a/MeshGeoToolsLib/BoundaryElementsOnSurface.h b/MeshGeoToolsLib/BoundaryElementsOnSurface.h
index 5cfc2dd14c82e7ec685fde6b52b9326e51ba1ab6..f4e31f8f3da0d08661f2c126a65544d740050226 100644
--- a/MeshGeoToolsLib/BoundaryElementsOnSurface.h
+++ b/MeshGeoToolsLib/BoundaryElementsOnSurface.h
@@ -5,8 +5,7 @@
  *              See accompanying file LICENSE.txt or
  *              http://www.opengeosys.org/LICENSE.txt
  */
-#ifndef BOUNDARYELEMENTSONSURFACE_H_
-#define BOUNDARYELEMENTSONSURFACE_H_
+#pragma once
 
 #include <vector>
 
@@ -65,5 +64,3 @@ private:
 };
 
 } // end namespace MeshGeoToolsLib
-
-#endif /* BOUNDARYELEMENTSONSURFACE_H_ */
diff --git a/MeshGeoToolsLib/BoundaryElementsSearcher.h b/MeshGeoToolsLib/BoundaryElementsSearcher.h
index 8636a0c80ad402763039e41381df34f4d4451e37..ad2d66ef262baf15035322cabb5edf51b880d8b8 100644
--- a/MeshGeoToolsLib/BoundaryElementsSearcher.h
+++ b/MeshGeoToolsLib/BoundaryElementsSearcher.h
@@ -5,8 +5,7 @@
  *              See accompanying file LICENSE.txt or
  *              http://www.opengeosys.org/LICENSE.txt
  */
-#ifndef BOUNDARYELEMENTSSEARCHER_H_
-#define BOUNDARYELEMENTSSEARCHER_H_
+#pragma once
 
 #include <vector>
 
@@ -87,5 +86,3 @@ private:
 };
 
 } // end namespace MeshGeoToolsLib
-
-#endif /* BOUNDARYELEMENTSSEARCHER_H_ */
diff --git a/MeshGeoToolsLib/GeoMapper.h b/MeshGeoToolsLib/GeoMapper.h
index 795bb0f465a52ebe5fffc3b5fc9e21ea9b894735..35b348f405e984d4687148df5649e31c623b6af3 100644
--- a/MeshGeoToolsLib/GeoMapper.h
+++ b/MeshGeoToolsLib/GeoMapper.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef GEOMAPPER_H
-#define GEOMAPPER_H
+#pragma once
 
 #include <cstddef>
 #include <vector>
@@ -95,5 +94,3 @@ private:
 };
 
 } // end namespace MeshGeoToolsLib
-
-#endif //GEOMAPPER_H
diff --git a/MeshGeoToolsLib/HeuristicSearchLength.h b/MeshGeoToolsLib/HeuristicSearchLength.h
index 0d8a57d84d2af2ef0b4d3d183deb08657507e4fc..79bbf6a82342948520ac815173c5e1f142cbf0d9 100644
--- a/MeshGeoToolsLib/HeuristicSearchLength.h
+++ b/MeshGeoToolsLib/HeuristicSearchLength.h
@@ -9,8 +9,7 @@
  *              http://www.opengeosys.org/LICENSE.txt
  */
 
-#ifndef HEURISTICSEARCHLENGTH_H_
-#define HEURISTICSEARCHLENGTH_H_
+#pragma once
 
 #include "MeshGeoToolsLib/SearchLength.h"
 
@@ -50,6 +49,3 @@ private:
 };
 
 } // end namespace MeshGeoToolsLib
-
-#endif
-
diff --git a/MeshGeoToolsLib/MeshNodeSearcher.h b/MeshGeoToolsLib/MeshNodeSearcher.h
index f2ab2358ef42e31ebfe8f7e79edec2b222a9c2e7..fdd432e4039a0c4c755be33de9bfb6596d67cbcd 100644
--- a/MeshGeoToolsLib/MeshNodeSearcher.h
+++ b/MeshGeoToolsLib/MeshNodeSearcher.h
@@ -7,8 +7,7 @@
  *              See accompanying file LICENSE.txt or
  *              http://www.opengeosys.org/LICENSE.txt
  */
-#ifndef MESHNODESEARCHER_H_
-#define MESHNODESEARCHER_H_
+#pragma once
 
 #include <memory>
 #include <vector>
@@ -151,5 +150,3 @@ private:
 };
 
 } // end namespace MeshGeoToolsLib
-
-#endif /* MESHNODESEARCHER_H_ */
diff --git a/MeshGeoToolsLib/MeshNodesAlongPolyline.h b/MeshGeoToolsLib/MeshNodesAlongPolyline.h
index 3875cb4ce306bac626e0c8c8f9888fc68c13bd5d..e90ed01458a8306b3590cbe163f7a6aad60933ff 100644
--- a/MeshGeoToolsLib/MeshNodesAlongPolyline.h
+++ b/MeshGeoToolsLib/MeshNodesAlongPolyline.h
@@ -10,8 +10,7 @@
  *              http://www.opengeosys.org/LICENSE.txt
  */
 
-#ifndef MESHNODESALONGPOLYLINE_H_
-#define MESHNODESALONGPOLYLINE_H_
+#pragma once
 
 #include <vector>
 
@@ -77,5 +76,3 @@ private:
     std::vector<double> _dist_of_proj_node_from_ply_start;
 };
 } // end namespace MeshGeoToolsLib
-
-#endif /* MESHNODESALONGPOLYLINE_H_ */
diff --git a/MeshGeoToolsLib/MeshNodesAlongSurface.h b/MeshGeoToolsLib/MeshNodesAlongSurface.h
index 91aea451beaf14dcb4aa1012eb8b3ada305ae4ab..c8a1c85b266211c1635c6e9d9b1c302df1f29d64 100644
--- a/MeshGeoToolsLib/MeshNodesAlongSurface.h
+++ b/MeshGeoToolsLib/MeshNodesAlongSurface.h
@@ -10,8 +10,7 @@
  *
  */
 
-#ifndef MESHNODESALONGSURFACE_H_
-#define MESHNODESALONGSURFACE_H_
+#pragma once
 
 #include <vector>
 
@@ -69,5 +68,3 @@ private:
     std::vector<std::size_t> _msh_node_ids;
 };
 } // end namespace MeshGeoToolsLib
-
-#endif /* MESHNODESALONGSURFACE_H_ */
diff --git a/MeshGeoToolsLib/MeshNodesOnPoint.h b/MeshGeoToolsLib/MeshNodesOnPoint.h
index da669243153bd106ddcc2d6363e1e1ffa03decc9..11b5b477293e934b27a3d4b0153585368d10b6b6 100644
--- a/MeshGeoToolsLib/MeshNodesOnPoint.h
+++ b/MeshGeoToolsLib/MeshNodesOnPoint.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/LICENSE.txt
  */
 
-#ifndef MESHNODESONPOINT_H_
-#define MESHNODESONPOINT_H_
+#pragma once
 
 #include <vector>
 
@@ -63,5 +62,3 @@ private:
     std::vector<std::size_t> _msh_node_ids;
 };
 } // end namespace MeshGeoToolsLib
-
-#endif /* MESHNODESONPOINT_H_ */
diff --git a/MeshGeoToolsLib/SearchLength.h b/MeshGeoToolsLib/SearchLength.h
index 4b8877ab50e5c955f821c8ceb485751225bf011a..8b72d59be71d959bdaf73d3f3884794a75d39083 100644
--- a/MeshGeoToolsLib/SearchLength.h
+++ b/MeshGeoToolsLib/SearchLength.h
@@ -9,8 +9,7 @@
  *              http://www.opengeosys.org/LICENSE.txt
  */
 
-#ifndef SEARCHLENGTH_H_
-#define SEARCHLENGTH_H_
+#pragma once
 
 namespace MeshGeoToolsLib
 {
@@ -42,6 +41,3 @@ protected:
 };
 
 } // end namespace MeshGeoToolsLib
-
-#endif
-
diff --git a/MeshLib/CoordinateSystem.h b/MeshLib/CoordinateSystem.h
index d2e2b9c5f61e986ce93c1ca9b73367d4e62947c2..f8ed88db0b490f8f1d9c53be9e45bebef1259046 100644
--- a/MeshLib/CoordinateSystem.h
+++ b/MeshLib/CoordinateSystem.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef COORDINATESYSTEMTYPE_H_
-#define COORDINATESYSTEMTYPE_H_
+#pragma once
 
 #include <cmath>
 
@@ -78,5 +77,3 @@ private:
 };
 
 } // MeshLib
-
-#endif // COORDINATESYSTEMTYPE_H_
diff --git a/MeshLib/ElementCoordinatesMappingLocal.h b/MeshLib/ElementCoordinatesMappingLocal.h
index 6b4c8ffcc0d8cd5a6bcb125291b43f5d3cecab2d..3185b911f3c8b273952d4cb5fe4b080719460f67 100644
--- a/MeshLib/ElementCoordinatesMappingLocal.h
+++ b/MeshLib/ElementCoordinatesMappingLocal.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef ELEMENTCOORDINATESMAPPINGLOCAL_H_
-#define ELEMENTCOORDINATESMAPPINGLOCAL_H_
+#pragma once
 
 #include <vector>
 #include <Eigen/Eigen>
@@ -54,5 +53,3 @@ private:
 };
 
 }
-
-#endif // ELEMENTCOORDINATESMAPPINGLOCAL_H_
diff --git a/MeshLib/ElementStatus.h b/MeshLib/ElementStatus.h
index 2240dfeb955ed27299747b9e040a179d7193e185..3ca2a5b99d80fbf42dc9d87a21ff349e38b72301 100644
--- a/MeshLib/ElementStatus.h
+++ b/MeshLib/ElementStatus.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef ELEMENTSTATUS_H_
-#define ELEMENTSTATUS_H_
+#pragma once
 
 #include <vector>
 
@@ -73,5 +72,3 @@ protected:
 }; /* class */
 
 } /* namespace */
-
-#endif /* ELEMENTSTATUS_H_ */
diff --git a/MeshLib/Elements/CellRule.h b/MeshLib/Elements/CellRule.h
index 02a178b762cb897a6ffa9b0a05b8cca5779ae193..620dd224122dbd6b453397af8cd341338471b5b6 100644
--- a/MeshLib/Elements/CellRule.h
+++ b/MeshLib/Elements/CellRule.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef CELLRULE_H_
-#define CELLRULE_H_
+#pragma once
 
 namespace MeshLib
 {
@@ -33,6 +32,3 @@ public:
 }; /* class */
 
 } /* namespace */
-
-#endif /* CELLRULE_H_ */
-
diff --git a/MeshLib/Elements/EdgeReturn.h b/MeshLib/Elements/EdgeReturn.h
index 74a5b85272e6268b5b5ca6b48845ca64f3872ccf..db3f5ba298c327fcc1c969c9f4da67d0c849781c 100644
--- a/MeshLib/Elements/EdgeReturn.h
+++ b/MeshLib/Elements/EdgeReturn.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef EDGERETURN_H_
-#define EDGERETURN_H_
+#pragma once
 
 namespace MeshLib
 {
@@ -43,7 +42,3 @@ public:
 };
 
 } // end MeshLib
-
-
-#endif /* EDGERETURN_H_ */
-
diff --git a/MeshLib/Elements/EdgeRule.h b/MeshLib/Elements/EdgeRule.h
index b5325e3df0a09669211843480c335cd6e69f73db..9a9884e362fd4ce4e7ac32994f735aa779f0745c 100644
--- a/MeshLib/Elements/EdgeRule.h
+++ b/MeshLib/Elements/EdgeRule.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef EDGERULE_H_
-#define EDGERULE_H_
+#pragma once
 
 namespace MeshLib
 {
@@ -39,6 +38,3 @@ public:
 }; /* class */
 
 } /* namespace */
-
-#endif /* EDGERULE_H_ */
-
diff --git a/MeshLib/Elements/Element.h b/MeshLib/Elements/Element.h
index a4b2a5c56cbf07de8390a9ce45f64d32a11f7c30..1aefc52267a3e25aa976ce754b0cb220a7ead717 100644
--- a/MeshLib/Elements/Element.h
+++ b/MeshLib/Elements/Element.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef ELEMENT_H_
-#define ELEMENT_H_
+#pragma once
 
 #include <limits>
 #include <boost/optional.hpp>
@@ -232,6 +231,3 @@ protected:
 bool isPointInElementXY(MathLib::Point3d const& p, Element const& e);
 
 } /* namespace */
-
-#endif /* ELEMENT_H_ */
-
diff --git a/MeshLib/Elements/ElementErrorCode.h b/MeshLib/Elements/ElementErrorCode.h
index b468137129ca4c30e814bea3d23aecf559ba49ac..ac284ae897b9a0bd11289ff6b45778b2b2043b2b 100644
--- a/MeshLib/Elements/ElementErrorCode.h
+++ b/MeshLib/Elements/ElementErrorCode.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef ELEMENTERRORCODES_H
-#define ELEMENTERRORCODES_H
+#pragma once
 
 #include <bitset>
 #include <string>
@@ -61,6 +60,3 @@ public:
 private:
 
 };
-
-
-#endif //ELEMENTERRORCODES_H
diff --git a/MeshLib/Elements/Elements.h b/MeshLib/Elements/Elements.h
index 718c95ec5fddfde26365a41031b580fdfdbb3fee..9e9ecbe6e19de75d4b23a3ff30e8622970f3dfe8 100644
--- a/MeshLib/Elements/Elements.h
+++ b/MeshLib/Elements/Elements.h
@@ -10,8 +10,7 @@
  *
  */
 
-#ifndef MESHLIB_ELEMENTS_ELEMENTS_H_
-#define MESHLIB_ELEMENTS_ELEMENTS_H_
+#pragma once
 
 #include "MeshLib/Elements/Element.h"
 #include "MeshLib/Elements/Line.h"
@@ -22,5 +21,3 @@
 #include "MeshLib/Elements/Quad.h"
 #include "MeshLib/Elements/Tet.h"
 #include "MeshLib/Elements/Tri.h"
-
-#endif  // MESHLIB_ELEMENTS_ELEMENTS_H_
diff --git a/MeshLib/Elements/FaceRule.h b/MeshLib/Elements/FaceRule.h
index 21d45df77b56f3158801796cd617a63b54832d3d..45c5970ec4a26ed01fdd9caa82382d493aa64a41 100644
--- a/MeshLib/Elements/FaceRule.h
+++ b/MeshLib/Elements/FaceRule.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef FACERULE_H_
-#define FACERULE_H_
+#pragma once
 
 #include "MathLib/Vector3.h"
 #include "Element.h"
@@ -40,6 +39,3 @@ public:
 }; /* class */
 
 } /* namespace */
-
-#endif /* FACERULE_H_ */
-
diff --git a/MeshLib/Elements/Hex.h b/MeshLib/Elements/Hex.h
index 751646b3674998efe6bdb73a932271caaf46ba49..9bb14dc6ab0d2bba0a5975b231a6feae4ab3cb73 100644
--- a/MeshLib/Elements/Hex.h
+++ b/MeshLib/Elements/Hex.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef HEX_H_
-#define HEX_H_
+#pragma once
 
 #include "TemplateElement.h"
 #include "HexRule8.h"
@@ -26,5 +25,3 @@ namespace MeshLib {
 typedef TemplateElement<HexRule8> Hex;
 typedef TemplateElement<HexRule20> Hex20;
 }
-
-#endif /* HEX_H_ */
diff --git a/MeshLib/Elements/HexRule20.h b/MeshLib/Elements/HexRule20.h
index 5d1c442bc231ecbe7cd044a01fd3f86f3c0c36a0..efc53b437e4fedb6a9588ea20c4e1fe43982dd99 100644
--- a/MeshLib/Elements/HexRule20.h
+++ b/MeshLib/Elements/HexRule20.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef HEXRULE20_H_
-#define HEXRULE20_H_
+#pragma once
 
 #include "MeshLib/MeshEnums.h"
 #include "Element.h"
@@ -67,6 +66,3 @@ public:
 }; /* class */
 
 } /* namespace */
-
-#endif /* HEXRULE20_H_ */
-
diff --git a/MeshLib/Elements/HexRule8.h b/MeshLib/Elements/HexRule8.h
index 7d931592791107425d0d9fea4bf3818179b5604c..b1de7ac555680cabe440fbf3dd7460e8333e0026 100644
--- a/MeshLib/Elements/HexRule8.h
+++ b/MeshLib/Elements/HexRule8.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef HEXRULE8_H_
-#define HEXRULE8_H_
+#pragma once
 
 #include "MeshLib/MeshEnums.h"
 #include "Element.h"
@@ -100,6 +99,3 @@ public:
 }; /* class */
 
 } /* namespace */
-
-#endif /* HEXRULE_H_ */
-
diff --git a/MeshLib/Elements/Line.h b/MeshLib/Elements/Line.h
index 221fc90c2f7c76183a300a864d8a171cd95c9bdc..c4ef9440fa22d68597eeb3336a6f6ff0c1194340 100644
--- a/MeshLib/Elements/Line.h
+++ b/MeshLib/Elements/Line.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef LINE_H_
-#define LINE_H_
+#pragma once
 
 #include "TemplateElement.h"
 #include "LineRule2.h"
@@ -28,6 +27,3 @@ typedef TemplateElement<LineRule2> Line;
 typedef TemplateElement<LineRule3> Line3;
 
 }
-
-
-#endif /* LINE_H_ */
diff --git a/MeshLib/Elements/LineRule2.h b/MeshLib/Elements/LineRule2.h
index 89f63f979b86d1e9984455cfbb31657553467380..52b6b494ede8a48d7e85b74ab84e18d42615b372 100644
--- a/MeshLib/Elements/LineRule2.h
+++ b/MeshLib/Elements/LineRule2.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef LINERULE2_H_
-#define LINERULE2_H_
+#pragma once
 
 #include "MeshLib/MeshEnums.h"
 #include "Element.h"
@@ -69,6 +68,3 @@ public:
 }; /* class */
 
 } /* namespace */
-
-#endif /* LINERULE2_H_ */
-
diff --git a/MeshLib/Elements/LineRule3.h b/MeshLib/Elements/LineRule3.h
index 2d5b52786dd64924bc4c659c3b715e7d9098c1f9..8489a8167faaf4497c1cc34e98a7fc7cec48a8fc 100644
--- a/MeshLib/Elements/LineRule3.h
+++ b/MeshLib/Elements/LineRule3.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef LINERULE3_H_
-#define LINERULE3_H_
+#pragma once
 
 #include "MeshLib/MeshEnums.h"
 #include "LineRule2.h"
@@ -36,6 +35,3 @@ public:
 }; /* class */
 
 } /* namespace */
-
-#endif /* LINERULE3_H_ */
-
diff --git a/MeshLib/Elements/Point.h b/MeshLib/Elements/Point.h
index 0c14fb588ee64bb584b03691f73c8afe2863c662..953aaa5fc592c5a1468e893768375a8ba6d4405f 100644
--- a/MeshLib/Elements/Point.h
+++ b/MeshLib/Elements/Point.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MESHLIB_POINT_H_
-#define MESHLIB_POINT_H_
+#pragma once
 
 #include "TemplateElement.h"
 #include "PointRule1.h"
@@ -19,5 +18,3 @@ namespace MeshLib
 {
     using Point = TemplateElement<PointRule1>;
 }
-
-#endif  // MESHLIB_POINT_H_
diff --git a/MeshLib/Elements/PointRule1.h b/MeshLib/Elements/PointRule1.h
index 775420795b779f4149993ca53b9567e1f37a6687..59f89ec3e27bc31707686a8ee3cdc81da3872e46 100644
--- a/MeshLib/Elements/PointRule1.h
+++ b/MeshLib/Elements/PointRule1.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MESHLIB_POINTRULE1_H_
-#define MESHLIB_POINTRULE1_H_
+#pragma once
 
 #include "MeshLib/MeshEnums.h"
 #include "Element.h"
@@ -62,6 +61,3 @@ public:
     static double computeVolume(Node const* const* _nodes);
 };
 }
-
-#endif  // MESHLIB_POINTRULE1_H_
-
diff --git a/MeshLib/Elements/Prism.h b/MeshLib/Elements/Prism.h
index 68461b17a27b200a6227947d05896e64412a7267..7176cfd79970c42b1d276295aae22067a24b8fa5 100644
--- a/MeshLib/Elements/Prism.h
+++ b/MeshLib/Elements/Prism.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef PRISM_H_
-#define PRISM_H_
+#pragma once
 
 #include "TemplateElement.h"
 #include "PrismRule6.h"
@@ -28,5 +27,3 @@ typedef TemplateElement<PrismRule6> Prism;
 typedef TemplateElement<PrismRule15> Prism15;
 
 }
-
-#endif /* PRISM_H_ */
diff --git a/MeshLib/Elements/PrismRule15.h b/MeshLib/Elements/PrismRule15.h
index 1fac76aee56aba9720b636d5acddccd006347428..4f6bb721b124e49f20f79020a0c5174c5a843c03 100644
--- a/MeshLib/Elements/PrismRule15.h
+++ b/MeshLib/Elements/PrismRule15.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PRISMRULE15_H_
-#define PRISMRULE15_H_
+#pragma once
 
 #include "MeshLib/MeshEnums.h"
 #include "Element.h"
@@ -68,6 +67,3 @@ public:
 }; /* class */
 
 } /* namespace */
-
-#endif /* PRISMRULE15_H_ */
-
diff --git a/MeshLib/Elements/PrismRule6.h b/MeshLib/Elements/PrismRule6.h
index 93472f614f3950a0e914cf10fc7bc420f3b9651d..aecd28b2159325d23fcd2332d2395edf55ce6830 100644
--- a/MeshLib/Elements/PrismRule6.h
+++ b/MeshLib/Elements/PrismRule6.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PRISMRULE6_H_
-#define PRISMRULE6_H_
+#pragma once
 
 #include "MeshLib/MeshEnums.h"
 #include "Element.h"
@@ -101,6 +100,3 @@ public:
 }; /* class */
 
 } /* namespace */
-
-#endif /* PRISMRULE6_H_ */
-
diff --git a/MeshLib/Elements/Pyramid.h b/MeshLib/Elements/Pyramid.h
index 67bba3c00732275e6b1f29c71fed2b6156b3fc0e..3ae5204c4cc90a4f6b88269da8280ed484b68ac4 100644
--- a/MeshLib/Elements/Pyramid.h
+++ b/MeshLib/Elements/Pyramid.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef PYRAMID_H_
-#define PYRAMID_H_
+#pragma once
 
 #include "TemplateElement.h"
 #include "PyramidRule5.h"
@@ -28,5 +27,3 @@ typedef TemplateElement<PyramidRule5> Pyramid;
 typedef TemplateElement<PyramidRule13> Pyramid13;
 
 }
-
-#endif /* PYRAMID_H_ */
diff --git a/MeshLib/Elements/PyramidRule13.h b/MeshLib/Elements/PyramidRule13.h
index 0baa3e8ea0385cf51716e2ef4daceb8ce9b76260..987a6fc17e7dcce0c6f4ed95dcbeb78090c4cee6 100644
--- a/MeshLib/Elements/PyramidRule13.h
+++ b/MeshLib/Elements/PyramidRule13.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PYRAMIDRULE13_H_
-#define PYRAMIDRULE13_H_
+#pragma once
 
 #include "MeshLib/MeshEnums.h"
 #include "Element.h"
@@ -67,6 +66,3 @@ public:
 }; /* class */
 
 } /* namespace */
-
-#endif /* PYRAMIDRULE13_H_ */
-
diff --git a/MeshLib/Elements/PyramidRule5.h b/MeshLib/Elements/PyramidRule5.h
index 8c8a9b6c63916560cd0626b4dd82b8579fdc987b..f1864743898ccb7e196e0ca1dfc7e01fca969f60 100644
--- a/MeshLib/Elements/PyramidRule5.h
+++ b/MeshLib/Elements/PyramidRule5.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PYRAMIDRULE5_H_
-#define PYRAMIDRULE5_H_
+#pragma once
 
 #include "MeshLib/MeshEnums.h"
 #include "Element.h"
@@ -100,6 +99,3 @@ public:
 }; /* class */
 
 } /* namespace */
-
-#endif /* PYRAMIDRULE5_H_ */
-
diff --git a/MeshLib/Elements/Quad.h b/MeshLib/Elements/Quad.h
index f4b4730748e3c992163049afe7aa6838d4e56b0c..ad1cd724d0301d138987e5f988b57085945ddc98 100644
--- a/MeshLib/Elements/Quad.h
+++ b/MeshLib/Elements/Quad.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef QUAD_H_
-#define QUAD_H_
+#pragma once
 
 #include "TemplateElement.h"
 #include "QuadRule4.h"
@@ -32,5 +31,3 @@ typedef TemplateElement<QuadRule8> Quad8;
 typedef TemplateElement<QuadRule9> Quad9;
 
 }
-
-#endif /* QUAD_H_ */
diff --git a/MeshLib/Elements/QuadRule4.h b/MeshLib/Elements/QuadRule4.h
index 5f1409f482c8f9cce41e22a261d79e9d8595c909..31af81dfe9ce7b5ad89e009868556231de64dd98 100644
--- a/MeshLib/Elements/QuadRule4.h
+++ b/MeshLib/Elements/QuadRule4.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef QUADRULE4_H_
-#define QUADRULE4_H_
+#pragma once
 
 #include "MeshLib/MeshEnums.h"
 #include "Element.h"
@@ -82,6 +81,3 @@ public:
 }; /* class */
 
 } /* namespace */
-
-#endif /* QUADRULE4_H_ */
-
diff --git a/MeshLib/Elements/QuadRule8.h b/MeshLib/Elements/QuadRule8.h
index f83290ab523b2e2ac9debc5852ca974872a81aad..e29b2d2fb6a72033382915d420675093ec64dfb9 100644
--- a/MeshLib/Elements/QuadRule8.h
+++ b/MeshLib/Elements/QuadRule8.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef QUADRULE8_H_
-#define QUADRULE8_H_
+#pragma once
 
 #include "MeshLib/MeshEnums.h"
 #include "QuadRule4.h"
@@ -51,6 +50,3 @@ public:
 }; /* class */
 
 } /* namespace */
-
-#endif /* QUADRULE8_H_ */
-
diff --git a/MeshLib/Elements/QuadRule9.h b/MeshLib/Elements/QuadRule9.h
index 47894bcff18688e2025093699886aa7491ffee44..af33b4ba281a5d46801c55bd5ba462e708f95346 100644
--- a/MeshLib/Elements/QuadRule9.h
+++ b/MeshLib/Elements/QuadRule9.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef QUADRULE9_H_
-#define QUADRULE9_H_
+#pragma once
 
 #include "MeshLib/MeshEnums.h"
 #include "QuadRule8.h"
@@ -43,6 +42,3 @@ public:
 }; /* class */
 
 } /* namespace */
-
-#endif /* QUADRULE9_H_ */
-
diff --git a/MeshLib/Elements/TemplateElement.h b/MeshLib/Elements/TemplateElement.h
index 39e36b03bdd894ae55ba4ad351479e991acc7f31..1a69946aa186f09cebdf5e8497edf50f6ddfed7d 100644
--- a/MeshLib/Elements/TemplateElement.h
+++ b/MeshLib/Elements/TemplateElement.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef TEMPLATEELEMENT_H_
-#define TEMPLATEELEMENT_H_
+#pragma once
 
 #include <array>
 #include <limits>
@@ -158,6 +157,3 @@ public:
 } // MeshLib
 
 #include "TemplateElement-impl.h"
-
-#endif /* TEMPLATEELEMENT_H_ */
-
diff --git a/MeshLib/Elements/Tet.h b/MeshLib/Elements/Tet.h
index 297a09ea0c0333c3018040aa9677d9b636ee2c28..ba4546c281eb188d228e1ac7236ca2509d0c3d25 100644
--- a/MeshLib/Elements/Tet.h
+++ b/MeshLib/Elements/Tet.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef TET_H_
-#define TET_H_
+#pragma once
 
 #include "TemplateElement.h"
 #include "TetRule4.h"
@@ -28,5 +27,3 @@ typedef TemplateElement<TetRule4> Tet;
 typedef TemplateElement<TetRule10> Tet10;
 
 }
-
-#endif /* TET_H_ */
diff --git a/MeshLib/Elements/TetRule10.h b/MeshLib/Elements/TetRule10.h
index fd627bf061c418bb0bbd08bd466f9261d5d56a76..cbb57b58a72d8c4ed199924a0ce261e53de7cad4 100644
--- a/MeshLib/Elements/TetRule10.h
+++ b/MeshLib/Elements/TetRule10.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef TETRULE10_H_
-#define TETRULE10_H_
+#pragma once
 
 #include "MeshLib/MeshEnums.h"
 #include "Element.h"
@@ -62,6 +61,3 @@ public:
 }; /* class */
 
 } /* namespace */
-
-#endif /* TETRULE10_H_ */
-
diff --git a/MeshLib/Elements/TetRule4.h b/MeshLib/Elements/TetRule4.h
index 1f7eb407d2a726576f4c532037a7e30df99aac2d..745b9326b54f20000893e489ad84e7eae13a3ab7 100644
--- a/MeshLib/Elements/TetRule4.h
+++ b/MeshLib/Elements/TetRule4.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef TETRULE4_H_
-#define TETRULE4_H_
+#pragma once
 
 #include "MeshLib/MeshEnums.h"
 #include "Element.h"
@@ -95,6 +94,3 @@ public:
 }; /* class */
 
 } /* namespace */
-
-#endif /* TETRULE4_H_ */
-
diff --git a/MeshLib/Elements/Tri.h b/MeshLib/Elements/Tri.h
index 2b5fbfe85446373b558c4d2b9ba80a3d84c69d9a..ab67c61108466924b7b3a9273a8c2287f61083b5 100644
--- a/MeshLib/Elements/Tri.h
+++ b/MeshLib/Elements/Tri.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef TRI_H_
-#define TRI_H_
+#pragma once
 
 #include "TemplateElement.h"
 #include "TriRule3.h"
@@ -29,5 +28,3 @@ typedef TemplateElement<TriRule3> Tri;
 typedef TemplateElement<TriRule6> Tri6;
 
 }
-
-#endif /* TRI_H_ */
diff --git a/MeshLib/Elements/TriRule3.h b/MeshLib/Elements/TriRule3.h
index 6a060081e77b0c610b6e915891c134b0b8abdf6a..f7f3c14c6c263ff8c5a6f08a8c6bba7aa173ba3b 100644
--- a/MeshLib/Elements/TriRule3.h
+++ b/MeshLib/Elements/TriRule3.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef TRIRULE3_H_
-#define TRIRULE3_H_
+#pragma once
 
 #include "MeshLib/MeshEnums.h"
 #include "Element.h"
@@ -83,6 +82,3 @@ public:
 }; /* class */
 
 } /* namespace */
-
-#endif /* TRIRULE3_H_ */
-
diff --git a/MeshLib/Elements/TriRule6.h b/MeshLib/Elements/TriRule6.h
index ec12465bd3c8b08ee7b899ef3ef1a987b8017b9f..d2b234cd0d2d9e7d6e11540d5fa453e2ed07d6ca 100644
--- a/MeshLib/Elements/TriRule6.h
+++ b/MeshLib/Elements/TriRule6.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef TRIRULE6_H_
-#define TRIRULE6_H_
+#pragma once
 
 #include "MeshLib/MeshEnums.h"
 #include "TriRule3.h"
@@ -54,6 +53,3 @@ public:
 }; /* class */
 
 } /* namespace */
-
-#endif /* TRIRULE6_H_ */
-
diff --git a/MeshLib/Elements/Utils.h b/MeshLib/Elements/Utils.h
index ee56bee41f15051a5d186f33dbedeceb399d17a4..c355142a40a25778878cdab37da31bfead0d3658 100644
--- a/MeshLib/Elements/Utils.h
+++ b/MeshLib/Elements/Utils.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MESHLIB_ELEMENTS_UTILS_H_
-#define MESHLIB_ELEMENTS_UTILS_H_
+#pragma once
 
 #include <algorithm>
 #include <vector>
@@ -41,5 +40,3 @@ inline std::vector<Node*> getBaseNodes(std::vector<Element*> const& elements)
 }
 
 }  // namespace MeshLib
-
-#endif  // MESHLIB_ELEMENTS_UTILS_H_
diff --git a/MeshLib/Elements/VertexRule.h b/MeshLib/Elements/VertexRule.h
index 09b809cfcf5fce2ab2a79b87055142c6675eb9e2..2651a4480431ed765f0ba99e64df4b67d373c57c 100644
--- a/MeshLib/Elements/VertexRule.h
+++ b/MeshLib/Elements/VertexRule.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MESHLIB_VERTEX_RULE_H
-#define MESHLIB_VERTEX_RULE_H
+#pragma once
 
 namespace MeshLib
 {
@@ -40,6 +39,3 @@ public:
 };
 
 }
-
-#endif // MESHLIB_VERTEX_RULE_H
-
diff --git a/MeshLib/IO/Legacy/MeshIO.h b/MeshLib/IO/Legacy/MeshIO.h
index 51c5152ecb3e1b4aae3bd60e104b19e69d0e3a86..dca1fae9a54dce47245677e61ee7a788d3000461 100644
--- a/MeshLib/IO/Legacy/MeshIO.h
+++ b/MeshLib/IO/Legacy/MeshIO.h
@@ -12,9 +12,7 @@
  *
  */
 
-
-#ifndef MESHIO_H_
-#define MESHIO_H_
+#pragma once
 
 #include <string>
 #include <vector>
@@ -68,5 +66,3 @@ private:
 } // end namespace Legacy
 } // end namespace IO
 } // end namespace MeshLib
-
-#endif /* MESHIO_H_ */
diff --git a/MeshLib/IO/MPI_IO/NodePartitionedMeshReader.h b/MeshLib/IO/MPI_IO/NodePartitionedMeshReader.h
index f9ccf81ec99388ca15a80cb863a299bdc5150a20..cf302e0fd76703933c28cb89027a98100e56c5c7 100644
--- a/MeshLib/IO/MPI_IO/NodePartitionedMeshReader.h
+++ b/MeshLib/IO/MPI_IO/NodePartitionedMeshReader.h
@@ -11,8 +11,7 @@
                http://www.opengeosys.org/project/license
  */
 
-#ifndef NODE_PARTITIONED_MESH_READER_H
-#define NODE_PARTITIONED_MESH_READER_H
+#pragma once
 
 #include <iosfwd>
 #include <string>
@@ -252,5 +251,3 @@ private:
 };
 }   // end namespace IO
 }   // end namespace MeshLib
-
-#endif  // READ_NODE_PARTITIONED_MESH_H
diff --git a/MeshLib/IO/VtkIO/PVDFile.h b/MeshLib/IO/VtkIO/PVDFile.h
index 237a17eed1f9e80d225f8f0ed85a9d1058302c8e..1e7e30ea278d85a27f11440cc16f8ea03dfe7769 100644
--- a/MeshLib/IO/VtkIO/PVDFile.h
+++ b/MeshLib/IO/VtkIO/PVDFile.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MESHLIB_VTKIO_PVDFILE_H
-#define MESHLIB_VTKIO_PVDFILE_H
+#pragma once
 
 #include <string>
 #include <vector>
@@ -37,5 +36,3 @@ private:
 
 } // namespace IO
 } // namespace MeshLib
-
-#endif // MESHLIB_VTKIO_PVDFILE_H
diff --git a/MeshLib/IO/VtkIO/VtuInterface.h b/MeshLib/IO/VtkIO/VtuInterface.h
index 0dcf69b00b07468f6c6364c24bee487215b3c600..b7463b4c0f4b58ac00b082dbfcb2577960f06cb3 100644
--- a/MeshLib/IO/VtkIO/VtuInterface.h
+++ b/MeshLib/IO/VtkIO/VtuInterface.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef VTUINTERFACE_H_
-#define VTUINTERFACE_H_
+#pragma once
 
 #include <string>
 #include <vtkXMLWriter.h>
@@ -59,5 +58,3 @@ private:
 } // end namespace MeshLib
 
 #include "VtuInterface-impl.h"
-
-#endif /* VTUINTERFACE_H_ */
diff --git a/MeshLib/IO/readMeshFromFile.h b/MeshLib/IO/readMeshFromFile.h
index def517e741b7bb2b61e146650a5ac0dc5688b042..8b2ce3d0935664663f3c30b20b4286f3eabc73b4 100644
--- a/MeshLib/IO/readMeshFromFile.h
+++ b/MeshLib/IO/readMeshFromFile.h
@@ -16,8 +16,7 @@
  * @author Karsten Rink
  */
 
-#ifndef READMESHFROMFILE_H
-#define READMESHFROMFILE_H
+#pragma once
 
 #include <string>
 
@@ -31,4 +30,3 @@ MeshLib::Mesh* readMeshFromFileSerial(const std::string &file_name);
 MeshLib::Mesh* readMeshFromFile(const std::string &file_name);
 }
 }
-#endif // READMESHFROMFILE_H
diff --git a/MeshLib/IO/writeMeshToFile.h b/MeshLib/IO/writeMeshToFile.h
index 4569a0aa6251eddc8f483775eca2e0e287aa533f..bd91dd447d5d2783db0f52cd7c33f25f7308e1c1 100644
--- a/MeshLib/IO/writeMeshToFile.h
+++ b/MeshLib/IO/writeMeshToFile.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef WRITEMESHTOFILE_H_
-#define WRITEMESHTOFILE_H_
+#pragma once
 
 #include <string>
 
@@ -19,5 +18,3 @@ namespace IO
 int writeMeshToFile(const MeshLib::Mesh &mesh, const std::string &file_name);
 }
 }
-
-#endif // WRITEMESHTOFILE_H_
diff --git a/MeshLib/Location.h b/MeshLib/Location.h
index 75a39b483824227b0e1ff5e26c3c12187d617700..64ddc761c0464c8e06780d7bbe8bbf1e412219e6 100644
--- a/MeshLib/Location.h
+++ b/MeshLib/Location.h
@@ -13,8 +13,7 @@
 #include <cstddef>
 #include <iosfwd>
 
-#ifndef LOCATION_H_
-#define LOCATION_H_
+#pragma once
 
 namespace MeshLib
 {
@@ -50,5 +49,3 @@ bool operator<(const Location& left, const Location& right)
 std::ostream& operator<<(std::ostream& os, Location const& l);
 
 }   // namespace MeshLib
-
-#endif  // LOCATION_H_
diff --git a/MeshLib/Mesh.h b/MeshLib/Mesh.h
index 4df518524a4d44ff628b6baa5ae6d4276c30f63e..9809e73e7b45cac63d0ea4d5ae2ffeba7e6bd9a2 100644
--- a/MeshLib/Mesh.h
+++ b/MeshLib/Mesh.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef MESH_H_
-#define MESH_H_
+#pragma once
 
 #include <cstdlib>
 #include <string>
@@ -236,6 +235,3 @@ void addPropertyToMesh(MeshLib::Mesh& mesh, std::string const& name,
 }
 
 } /* namespace */
-
-#endif /* MESH_H_ */
-
diff --git a/MeshLib/MeshEditing/AddLayerToMesh.h b/MeshLib/MeshEditing/AddLayerToMesh.h
index 07f9b522c0e59dae37af45c85ff9a99b786a2d48..6c71c16ca32773e3268aec637eeb343a343f6472 100644
--- a/MeshLib/MeshEditing/AddLayerToMesh.h
+++ b/MeshLib/MeshEditing/AddLayerToMesh.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef ADDLAYERTOMESH_H
-#define ADDLAYERTOMESH_H
+#pragma once
 
 #include <vector>
 #include <string>
@@ -43,5 +42,3 @@ MeshLib::Mesh* addLayerToMesh(MeshLib::Mesh const& mesh,
     bool on_top);
 
 } // end namespace MeshLib
-
-#endif //ADDLAYERTOMESH_H
diff --git a/MeshLib/MeshEditing/ConvertToLinearMesh.h b/MeshLib/MeshEditing/ConvertToLinearMesh.h
index 33462b62d76c64c279ce0d377d21a798a943d45a..40f541b64d70dd23e0b8dc97a688e11cca35a0a3 100644
--- a/MeshLib/MeshEditing/ConvertToLinearMesh.h
+++ b/MeshLib/MeshEditing/ConvertToLinearMesh.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MESHLIB_CONVERRTTOLINEARMESH_H_
-#define MESHLIB_CONVERRTTOLINEARMESH_H_
+#pragma once
 
 #include <memory>
 #include <string>
@@ -24,5 +23,3 @@ std::unique_ptr<MeshLib::Mesh> convertToLinearMesh(
     const MeshLib::Mesh& mesh, const std::string& new_mesh_name);
 
 } // end namespace MeshLib
-
-#endif //MESHLIB_CONVERRTTOLINEARMESH_H_
diff --git a/MeshLib/MeshEditing/DuplicateMeshComponents.h b/MeshLib/MeshEditing/DuplicateMeshComponents.h
index 9b506d14334ce77fef439270495b327b3ded98b0..a01567912913a93222949cf96e7a5ada604feb33 100644
--- a/MeshLib/MeshEditing/DuplicateMeshComponents.h
+++ b/MeshLib/MeshEditing/DuplicateMeshComponents.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef DUPLICATEMESHCOMPONENTS_H
-#define DUPLICATEMESHCOMPONENTS_H
+#pragma once
 
 #include <vector>
 
@@ -43,5 +42,3 @@ namespace MeshLib
     MeshLib::Element* copyElement(MeshLib::Element const*const element, const std::vector<MeshLib::Node*> &nodes);
 
 } // end namespace MeshLib
-
-#endif //DUPLICATEMESHCOMPONENTS_H
diff --git a/MeshLib/MeshEditing/ElementValueModification.h b/MeshLib/MeshEditing/ElementValueModification.h
index f9055412e74a303c9ba9b7b0da6c6c5d676f0147..8fa50b017b85d8f2784400c1c6b6345d95e125a6 100644
--- a/MeshLib/MeshEditing/ElementValueModification.h
+++ b/MeshLib/MeshEditing/ElementValueModification.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef MESHVALUEMODIFICATION_H
-#define MESHVALUEMODIFICATION_H
+#pragma once
 
 #include <vector>
 
@@ -77,5 +76,3 @@ private:
 };
 
 } // end namespace MeshLib
-
-#endif //MESHVALUEMODIFICATION_H
diff --git a/MeshLib/MeshEditing/FlipElements.h b/MeshLib/MeshEditing/FlipElements.h
index 365b29f208eebf0475c374f559aaef0133a0550d..94b587619f271c57a69a53682ecad70d3a9e7983 100644
--- a/MeshLib/MeshEditing/FlipElements.h
+++ b/MeshLib/MeshEditing/FlipElements.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef FLIPELEMENTS_H_
-#define FLIPELEMENTS_H_
+#pragma once
 
 #include <memory>
 #include <vector>
@@ -39,5 +38,3 @@ std::unique_ptr<MeshLib::Element> createFlippedElement(MeshLib::Element const& e
 std::unique_ptr<MeshLib::Mesh> createFlippedMesh(MeshLib::Mesh const& mesh);
 
 }
-
-#endif //FLIPELEMENTS_H_
diff --git a/MeshLib/MeshEditing/Mesh2MeshPropertyInterpolation.h b/MeshLib/MeshEditing/Mesh2MeshPropertyInterpolation.h
index 4b6bf548141a7c475182ae2dfa399a27eb9b583d..19d9be31016f52514d01bd309a1ada7fe29d88ae 100644
--- a/MeshLib/MeshEditing/Mesh2MeshPropertyInterpolation.h
+++ b/MeshLib/MeshEditing/Mesh2MeshPropertyInterpolation.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef MESH2MESHPROPERTYINTERPOLATION_H_
-#define MESH2MESHPROPERTYINTERPOLATION_H_
+#pragma once
 
 #include "MeshLib/PropertyVector.h"
 
@@ -70,5 +69,3 @@ private:
 };
 
 } // end namespace MeshLib
-
-#endif /* MESH2MESHPROPERTYINTERPOLATION_H_ */
diff --git a/MeshLib/MeshEditing/MeshRevision.h b/MeshLib/MeshEditing/MeshRevision.h
index 1545f5faa8a65196c4e21bc1b57bada1c2929dea..6eb0c294b5ea2339b6dc6a9125b0d2ece4257505 100644
--- a/MeshLib/MeshEditing/MeshRevision.h
+++ b/MeshLib/MeshEditing/MeshRevision.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef MESHREVISION_H_
-#define MESHREVISION_H_
+#pragma once
 
 #include <array>
 #include <limits>
@@ -192,5 +191,3 @@ private:
 };
 
 }
-
-#endif /* MESHREVISION_H_ */
diff --git a/MeshLib/MeshEditing/RemoveMeshComponents.h b/MeshLib/MeshEditing/RemoveMeshComponents.h
index 8ac0f182a2e12b0ad75da05cd1c177c01101594e..6ed2af75f39c056d45c4b873acc12ab003c14151 100644
--- a/MeshLib/MeshEditing/RemoveMeshComponents.h
+++ b/MeshLib/MeshEditing/RemoveMeshComponents.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef REMOVEMESHCOMPONENTS_H_
-#define REMOVEMESHCOMPONENTS_H_
+#pragma once
 
 #include <string>
 #include <vector>
@@ -38,5 +37,3 @@ MeshLib::Mesh* removeElements(const MeshLib::Mesh& mesh,
 MeshLib::Mesh* removeNodes(const MeshLib::Mesh &mesh, const std::vector<std::size_t> &removed_node_ids, const std::string &new_mesh_name);
 
 } // end namespace MeshLib
-
-#endif //REMOVEMESHCOMPONENTS_H_
diff --git a/MeshLib/MeshEditing/moveMeshNodes.h b/MeshLib/MeshEditing/moveMeshNodes.h
index ce44720e1b6d5df107ec417743e48de76f7f7dd8..27ef1fc4cdc17ef507e25d9d23a90c84398e646b 100644
--- a/MeshLib/MeshEditing/moveMeshNodes.h
+++ b/MeshLib/MeshEditing/moveMeshNodes.h
@@ -10,8 +10,7 @@
  *              See accompanying file LICENSE.txt or
  *              http://www.opengeosys.org/project/license
  */
-#ifndef MOVEMESHNODES_H_
-#define MOVEMESHNODES_H_
+#pragma once
 
 #include "MeshLib/Node.h"
 
@@ -44,5 +43,3 @@ void moveMeshNodes(
 };
 
 } // end namespace MeshLib
-
-#endif /* MOVEMESHNODES_H_ */
diff --git a/MeshLib/MeshEditing/projectMeshOntoPlane.h b/MeshLib/MeshEditing/projectMeshOntoPlane.h
index eff6010fa2c2d501cec165bdf9e74895fdadb364..a67eb231384ec05846e5314ecfc30d4292ff733e 100644
--- a/MeshLib/MeshEditing/projectMeshOntoPlane.h
+++ b/MeshLib/MeshEditing/projectMeshOntoPlane.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef PROJECTMESHONTOPLANE_H
-#define PROJECTMESHONTOPLANE_H
+#pragma once
 
 #include <vector>
 
@@ -57,5 +56,3 @@ MeshLib::Mesh* projectMeshOntoPlane(MeshLib::Mesh const& mesh,
 }
 
 } // end namespace MeshLib
-
-#endif //PROJECTMESHONTOPLANE_H
diff --git a/MeshLib/MeshEnums.h b/MeshLib/MeshEnums.h
index 7b75b5562f5fdd68d7550c20d00b94108361aab6..5a24cf9a24a11e71e8b29bb4c1c17ae05401c0e9 100644
--- a/MeshLib/MeshEnums.h
+++ b/MeshLib/MeshEnums.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef MESHENUMS_H
-#define MESHENUMS_H
+#pragma once
 
 #include <string>
 #include <vector>
@@ -108,5 +107,3 @@ const std::string CellType2String(const CellType t);
 const std::string MeshQualityType2String(const MeshQualityType t);
 
 }
-
-#endif //MESHENUMS_H
diff --git a/MeshLib/MeshGenerators/LayeredMeshGenerator.h b/MeshLib/MeshGenerators/LayeredMeshGenerator.h
index 02382618399663328a30dc26ac13ba56b2d4c70c..17cb36910fe30bd8ed62d0db0ed5e650e94817a8 100644
--- a/MeshLib/MeshGenerators/LayeredMeshGenerator.h
+++ b/MeshLib/MeshGenerators/LayeredMeshGenerator.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef LAYEREDMESHGENERATOR_H
-#define LAYEREDMESHGENERATOR_H
+#pragma once
 
 #include <memory>
 #include <limits>
@@ -99,5 +98,3 @@ protected:
     std::vector<MeshLib::Node*> _nodes;
     std::vector<MeshLib::Element*> _elements;
 };
-
-#endif //LAYEREDMESHGENERATOR_H
diff --git a/MeshLib/MeshGenerators/LayeredVolume.h b/MeshLib/MeshGenerators/LayeredVolume.h
index 7816784955ce5a10a704610fe777c1acd42cd928..a96a1a640196333da65bf8fd11495c4ffea51011 100644
--- a/MeshLib/MeshGenerators/LayeredVolume.h
+++ b/MeshLib/MeshGenerators/LayeredVolume.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef LAYEREDVOLUME_H
-#define LAYEREDVOLUME_H
+#pragma once
 
 #include <string>
 #include <vector>
@@ -63,5 +62,3 @@ private:
 
     std::vector<MeshLib::Node> _attribute_points;
 };
-
-#endif //LAYEREDVOLUME_H
diff --git a/MeshLib/MeshGenerators/MeshGenerator.h b/MeshLib/MeshGenerators/MeshGenerator.h
index 919fede8019ecea16d1b1bf9ef9ace8e41e46e46..4ae5725e4191d9d3366524cc6813706f8b6cf637 100644
--- a/MeshLib/MeshGenerators/MeshGenerator.h
+++ b/MeshLib/MeshGenerators/MeshGenerator.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MESHGENERATOR_H_
-#define MESHGENERATOR_H_
+#pragma once
 
 #include <array>
 #include <functional>
@@ -508,5 +507,3 @@ createSurfaceMesh(std::string const& mesh_name,
 
 }  //MeshGenerator
 } //MeshLib
-
-#endif //MESHGENERATOR_H_
diff --git a/MeshLib/MeshGenerators/MeshLayerMapper.h b/MeshLib/MeshGenerators/MeshLayerMapper.h
index 5a5428c9d1bbaeefd649e35a2dd8fbb718ae6099..382826b405eb0b71e1c9ef0da19442710aec3c95 100644
--- a/MeshLib/MeshGenerators/MeshLayerMapper.h
+++ b/MeshLib/MeshGenerators/MeshLayerMapper.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef MESHLAYERMAPPER_H
-#define MESHLAYERMAPPER_H
+#pragma once
 
 #include "LayeredMeshGenerator.h"
 
@@ -71,5 +70,3 @@ private:
 };
 
 } // end namespace MeshLib
-
-#endif //MESHLAYERMAPPER_H
diff --git a/MeshLib/MeshGenerators/RasterToMesh.h b/MeshLib/MeshGenerators/RasterToMesh.h
index 4c1efde00539ef92e6a988c1cc2a1e44f8139a76..e386f9694169c777a0f2857edb30d290c8254fec 100644
--- a/MeshLib/MeshGenerators/RasterToMesh.h
+++ b/MeshLib/MeshGenerators/RasterToMesh.h
@@ -8,8 +8,7 @@
  *
  */
 
-#ifndef RASTERTOMESH_H
-#define RASTERTOMESH_H
+#pragma once
 
 #include <logog/include/logog.hpp>
 
@@ -134,5 +133,3 @@ private:
 };
 
 } // end namespace MeshLib
-
-#endif // RASTERTOMESH_H
diff --git a/MeshLib/MeshGenerators/VtkMeshConverter.h b/MeshLib/MeshGenerators/VtkMeshConverter.h
index 2c15d32be38dee5a48c6449edf74006b6017989a..704c28cb131a9be12be1c14a7a7756b8276d686d 100644
--- a/MeshLib/MeshGenerators/VtkMeshConverter.h
+++ b/MeshLib/MeshGenerators/VtkMeshConverter.h
@@ -13,8 +13,7 @@
  *
  */
 
-#ifndef VTKMESHCONVERTER_H
-#define VTKMESHCONVERTER_H
+#pragma once
 
 #include <vtkDataArray.h>
 #include <vtkType.h>
@@ -119,5 +118,3 @@ private:
 };
 
 } // end namespace MeshLib
-
-#endif // VTKMESHCONVERTER_H
diff --git a/MeshLib/MeshInformation.h b/MeshLib/MeshInformation.h
index 52f3fe39a6bb416087d03de2664a40c4e0e516e6..867b4d9f2d561c88a897ca91d296f487f424efaf 100644
--- a/MeshLib/MeshInformation.h
+++ b/MeshLib/MeshInformation.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef MESHINFORMATION_H
-#define MESHINFORMATION_H
+#pragma once
 
 #include <array>
 #include <string>
@@ -71,5 +70,3 @@ public:
 };
 
 }
-
-#endif //MESHINFORMATION_H
diff --git a/MeshLib/MeshQuality/AngleSkewMetric.h b/MeshLib/MeshQuality/AngleSkewMetric.h
index c76e093da9aef3f4ae73caec5c53d23b6b680ac1..c7eee5a98e7fbd74f6a956c355bf812c8ecf7c3b 100644
--- a/MeshLib/MeshQuality/AngleSkewMetric.h
+++ b/MeshLib/MeshQuality/AngleSkewMetric.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef ANGLESKEWMETRIC_H_
-#define ANGLESKEWMETRIC_H_
+#pragma once
 
 #include "ElementQualityMetric.h"
 
@@ -45,5 +44,3 @@ private:
                                     double &min_angle, double &max_angle) const;
 };
 }
-
-#endif /* ANGLESKEWMETRIC_H_ */
diff --git a/MeshLib/MeshQuality/EdgeRatioMetric.h b/MeshLib/MeshQuality/EdgeRatioMetric.h
index 03c974eb23068267920df7ef935ee285731807d2..f7198e88d92b0fa3fc2020885a3eb198ef1ddf26 100644
--- a/MeshLib/MeshQuality/EdgeRatioMetric.h
+++ b/MeshLib/MeshQuality/EdgeRatioMetric.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef EDGERATIOMETRIC_H_
-#define EDGERATIOMETRIC_H_
+#pragma once
 
 #include "ElementQualityMetric.h"
 #include "MathLib/Point3d.h"
@@ -49,5 +48,3 @@ private:
     double checkHexahedron (std::vector<const MathLib::Point3d*> const& pnts) const;
 };
 }
-
-#endif /* EDGERATIOMETRIC_H_ */
diff --git a/MeshLib/MeshQuality/ElementQualityInterface.h b/MeshLib/MeshQuality/ElementQualityInterface.h
index 18b1c9a20f532b951b68bcce4bd8a682ee94eea7..0594c41d7da6515ec2fdf4e9bfae8d2e1c428095 100644
--- a/MeshLib/MeshQuality/ElementQualityInterface.h
+++ b/MeshLib/MeshQuality/ElementQualityInterface.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef ELEMENTQUALITYINTERFACE_H_
-#define ELEMENTQUALITYINTERFACE_H_
+#pragma once
 
 #include <vector>
 
@@ -109,5 +108,3 @@ private:
 };
 
 }
-
-#endif /* ELEMENTQUALITYINTERFACE_H_ */
diff --git a/MeshLib/MeshQuality/ElementQualityMetric.h b/MeshLib/MeshQuality/ElementQualityMetric.h
index c0a4c0fd1de6fb72f9dd0a6f95336bc04438fb21..3cc2607c5415721e72d798b10646c48a72754071 100644
--- a/MeshLib/MeshQuality/ElementQualityMetric.h
+++ b/MeshLib/MeshQuality/ElementQualityMetric.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef ELEMENTQUALITYMETRIC_H_
-#define ELEMENTQUALITYMETRIC_H_
+#pragma once
 
 #include <vector>
 
@@ -62,5 +61,3 @@ protected:
     std::vector<double> _element_quality_metric;
 };
 }
-
-#endif /* ELEMENTQUALITYMETRIC_H_ */
diff --git a/MeshLib/MeshQuality/ElementSizeMetric.h b/MeshLib/MeshQuality/ElementSizeMetric.h
index 6f4a1ffec4cd88f43686a05a0fd336d636864ea1..f7aa062f54c75302406fdfc31769e9c2fa63dce2 100644
--- a/MeshLib/MeshQuality/ElementSizeMetric.h
+++ b/MeshLib/MeshQuality/ElementSizeMetric.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef ELEMENTSIZEMETRIC_H_
-#define ELEMENTSIZEMETRIC_H_
+#pragma once
 
 #include "ElementQualityMetric.h"
 
@@ -37,5 +36,3 @@ private:
     std::size_t calc3dQuality();
 };
 }
-
-#endif /* ELEMENTSIZEMETRIC_H_ */
diff --git a/MeshLib/MeshQuality/MeshValidation.h b/MeshLib/MeshQuality/MeshValidation.h
index ab4d62b0298e67cd2f44714c78563ff654318249..391c226a2f59d4d407c731a1b3268ba8668fce76 100644
--- a/MeshLib/MeshQuality/MeshValidation.h
+++ b/MeshLib/MeshQuality/MeshValidation.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef MESHVALIDATION_H
-#define MESHVALIDATION_H
+#pragma once
 
 #include <array>
 #include <vector>
@@ -77,5 +76,3 @@ private:
 };
 
 } // end namespace MeshLib
-
-#endif //MESHVALIDATION_H
diff --git a/MeshLib/MeshQuality/RadiusEdgeRatioMetric.h b/MeshLib/MeshQuality/RadiusEdgeRatioMetric.h
index 8add8f07c315012884ab2b7c9826c87700ca2a26..da9fc775685270ff50d712faf4d497be1162dafc 100644
--- a/MeshLib/MeshQuality/RadiusEdgeRatioMetric.h
+++ b/MeshLib/MeshQuality/RadiusEdgeRatioMetric.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef RADIUSEDGERATIOMETRIC_H_
-#define RADIUSEDGERATIOMETRIC_H_
+#pragma once
 
 #include "ElementQualityMetric.h"
 
@@ -33,5 +32,3 @@ public:
     virtual void calculateQuality ();
 };
 }
-
-#endif /* RADIUSEDGERATIOMETRIC_H_ */
diff --git a/MeshLib/MeshQuality/SizeDifferenceMetric.h b/MeshLib/MeshQuality/SizeDifferenceMetric.h
index 1c4d77e4004554ca23f59767968a604d938161eb..399fd2385b534f26219190a4eaa9375c63087fac 100644
--- a/MeshLib/MeshQuality/SizeDifferenceMetric.h
+++ b/MeshLib/MeshQuality/SizeDifferenceMetric.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef SIZEDIFFERENCEMETRIC_H_
-#define SIZEDIFFERENCEMETRIC_H_
+#pragma once
 
 #include "ElementQualityMetric.h"
 
@@ -33,5 +32,3 @@ public:
     virtual void calculateQuality ();
 };
 }
-
-#endif /* SIZEDIFFERENCEMETRIC_H_ */
diff --git a/MeshLib/MeshSearch/ElementSearch.h b/MeshLib/MeshSearch/ElementSearch.h
index 881cfa63f31a05346f9107f6a072c0534ce6772a..80b48055953294422c76f06ea3e22f8e4d2b0341 100644
--- a/MeshLib/MeshSearch/ElementSearch.h
+++ b/MeshLib/MeshSearch/ElementSearch.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef ELEMENTSEARCH_H_
-#define ELEMENTSEARCH_H_
+#pragma once
 
 #include <limits>
 #include <vector>
@@ -97,5 +96,3 @@ private:
 };
 
 } // end namespace MeshLib
-
-#endif //ELEMENTEXTRACTION_H
diff --git a/MeshLib/MeshSearch/MeshElementGrid.h b/MeshLib/MeshSearch/MeshElementGrid.h
index 4399bd865c7157741a97609e3a3813b7bb123d11..18e718e021d8e9f15d9bf34141d93d970a1dee9f 100644
--- a/MeshLib/MeshSearch/MeshElementGrid.h
+++ b/MeshLib/MeshSearch/MeshElementGrid.h
@@ -8,8 +8,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef MESHELEMENTGRID_H_
-#define MESHELEMENTGRID_H_
+#pragma once
 
 #include <array>
 #include <limits>
@@ -105,5 +104,3 @@ void getGridGeometry(MeshLib::MeshElementGrid const& grid,
 #endif
 
 } // end namespace MeshLib
-
-#endif /* MESHELEMENTGRID_H_ */
diff --git a/MeshLib/MeshSearch/NodeSearch.h b/MeshLib/MeshSearch/NodeSearch.h
index 0523596b7d9e3f501e28094495d5a38d4ae107c0..1a9cdb36cddb98005fbc8d0c245fc9ead2de1523 100644
--- a/MeshLib/MeshSearch/NodeSearch.h
+++ b/MeshLib/MeshSearch/NodeSearch.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NODESEARCH_H_
-#define NODESEARCH_H_
+#pragma once
 
 #include <vector>
 
@@ -53,5 +52,3 @@ private:
 std::vector<Node*> getUniqueNodes(std::vector<Element*> const& elements);
 
 } // end namespace MeshLib
-
-#endif //NODESEARCH_H_
diff --git a/MeshLib/MeshSubset.h b/MeshLib/MeshSubset.h
index e8f83ba53590a580afde6ac0192c2a77d7f34c97..b10bae59627cf7dae4649391c4f7e19115b4c600 100644
--- a/MeshLib/MeshSubset.h
+++ b/MeshLib/MeshSubset.h
@@ -10,8 +10,7 @@
  *
  */
 
-#ifndef MESHSUBSET_H_
-#define MESHSUBSET_H_
+#pragma once
 
 #include <cassert>
 #include <vector>
@@ -170,5 +169,3 @@ private:
 };
 
 }   // namespace MeshLib
-
-#endif  // MESHSUBSET_H_
diff --git a/MeshLib/MeshSubsets.h b/MeshLib/MeshSubsets.h
index 69ad967fc34f3672736a0ab926345436c1991711..7e28bebdcba75f69b1d7a5e9c07b6c160cc91aef 100644
--- a/MeshLib/MeshSubsets.h
+++ b/MeshLib/MeshSubsets.h
@@ -10,8 +10,7 @@
  *
  */
 
-#ifndef MESHSUBSETS_H_
-#define MESHSUBSETS_H_
+#pragma once
 
 #include <algorithm>
 #include <cstdlib>
@@ -108,5 +107,3 @@ private:
 };
 
 }   // namespace MeshLib
-
-#endif    // MESHSUBSETS_H_
diff --git a/MeshLib/MeshSurfaceExtraction.h b/MeshLib/MeshSurfaceExtraction.h
index d1b04a75b42055bcfb4ecd66ca11f13b8246321f..c59d617e8abcf09a16c3b7aeddccbe66f2ab6de4 100644
--- a/MeshLib/MeshSurfaceExtraction.h
+++ b/MeshLib/MeshSurfaceExtraction.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef MESHSURFACEEXTRACTION_H
-#define MESHSURFACEEXTRACTION_H
+#pragma once
 
 #include <cstddef>
 #include <vector>
@@ -95,5 +94,3 @@ private:
 };
 
 } // end namespace MeshLib
-
-#endif //MESHSURFACEEXTRACTION_H
diff --git a/MeshLib/Node.h b/MeshLib/Node.h
index 215404b95d1965c9ea588005faf26e234a3fad9b..cc62d741ccdd3b46b623d989af09bb9b217b24b0 100644
--- a/MeshLib/Node.h
+++ b/MeshLib/Node.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef NODE_H_
-#define NODE_H_
+#pragma once
 
 #include <cstdlib>
 #include <limits>
@@ -104,6 +103,3 @@ protected:
 }; /* class */
 
 } /* namespace */
-
-#endif /* NODE_H_ */
-
diff --git a/MeshLib/NodeAdjacencyTable.h b/MeshLib/NodeAdjacencyTable.h
index 249baacb71f33ca8eaac6cc92a00c84314ad3d8a..c72d4ca99ad7b9ce473d78d6c4dabaee04b6b36d 100644
--- a/MeshLib/NodeAdjacencyTable.h
+++ b/MeshLib/NodeAdjacencyTable.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef MESHLIB_NODE_ADJACENCE_TABLE_H_
-#define MESHLIB_NODE_ADJACENCE_TABLE_H_
+#pragma once
 
 #include <algorithm>
 #include <vector>
@@ -81,5 +80,3 @@ private:
 };
 
 }   // namespace MeshLib
-
-#endif  //MESHLIB_NODE_ADJACENCE_TABLE_H_
diff --git a/MeshLib/NodePartitionedMesh.h b/MeshLib/NodePartitionedMesh.h
index 2cc5fe16ef8b3046de7c9f4479b1b5d4504adc86..f858ad3ac63691222e157309cde92c45f2054a51 100644
--- a/MeshLib/NodePartitionedMesh.h
+++ b/MeshLib/NodePartitionedMesh.h
@@ -13,8 +13,7 @@
 
 */
 
-#ifndef NODE_PARTITIONED_MESH_H_
-#define NODE_PARTITIONED_MESH_H_
+#pragma once
 
 #include <algorithm>
 #include <string>
@@ -175,5 +174,3 @@ class NodePartitionedMesh : public Mesh
 };
 
 }   // namespace MeshLib
-
-#endif // NODE_PARTITIONED_MESH_H_
diff --git a/MeshLib/Properties.h b/MeshLib/Properties.h
index 6d7d34606cbf1dd4a722e6b75cef5f77cb611faf..fcb5bfd9da50412b1fa5c2f7f5d8d2f4fe0f0b17 100644
--- a/MeshLib/Properties.h
+++ b/MeshLib/Properties.h
@@ -11,8 +11,7 @@
  *
  */
 
-#ifndef PROPERTIES_H_
-#define PROPERTIES_H_
+#pragma once
 
 #include <cstdlib>
 #include <string>
@@ -128,6 +127,3 @@ private:
 #include "Properties-impl.h"
 
 } // end namespace MeshLib
-
-#endif
-
diff --git a/MeshLib/PropertyVector.h b/MeshLib/PropertyVector.h
index a5baee161016a2e4dd02ea8889f578a477b5c38f..8117734547413bee1f1ba0bf78fde533e878f534 100644
--- a/MeshLib/PropertyVector.h
+++ b/MeshLib/PropertyVector.h
@@ -8,8 +8,7 @@
  *
  */
 
-#ifndef PROPERTYVECTOR_H_
-#define PROPERTYVECTOR_H_
+#pragma once
 
 #include <cassert>
 #include <iterator>
@@ -272,5 +271,3 @@ private:
 };
 
 } // end namespace MeshLib
-
-#endif
diff --git a/MeshLib/Vtk/VtkMappedMesh.h b/MeshLib/Vtk/VtkMappedMesh.h
index 36e945640f5d90a2dfc8e4c12ba44ee785ecfca8..bab5cfc07d51a05a7c4b36f970bc7a2d0aa589ca 100644
--- a/MeshLib/Vtk/VtkMappedMesh.h
+++ b/MeshLib/Vtk/VtkMappedMesh.h
@@ -14,8 +14,7 @@
  *
  */
 
-#ifndef VTKMAPPEDMESH_H_
-#define VTKMAPPEDMESH_H_
+#pragma once
 
 #include <vtkObject.h>
 #include <vtkMappedUnstructuredGrid.h>
@@ -73,5 +72,3 @@ private:
 vtkMakeMappedUnstructuredGrid(VtkMappedMesh, VtkMappedMeshImpl)
 
 } // end namespace
-
-#endif // VTKMAPPEDMESH_H_
diff --git a/MeshLib/Vtk/VtkMappedMeshSource.h b/MeshLib/Vtk/VtkMappedMeshSource.h
index c1c5540ceebc57ca9a15e7c070c2b36fd46236af..4c84f937d9efccf34d713136590bfa0a86153bb8 100644
--- a/MeshLib/Vtk/VtkMappedMeshSource.h
+++ b/MeshLib/Vtk/VtkMappedMeshSource.h
@@ -20,8 +20,7 @@
  *
  */
 
-#ifndef _VTKMAPPEDMESHSOURCE
-#define _VTKMAPPEDMESHSOURCE
+#pragma once
 
 #include <string>
 #include <vector>
@@ -113,5 +112,3 @@ private:
 };
 
 } // Namespace MeshLib
-
-#endif //_VTKMAPPEDMESHSOURCE
diff --git a/MeshLib/Vtk/VtkMappedPropertyVectorTemplate.h b/MeshLib/Vtk/VtkMappedPropertyVectorTemplate.h
index 4292af527a0bd94160b8d069837ab547b5b502d9..80b9436faef71f18c4ac2a92ebbfc5f12fcb37ea 100644
--- a/MeshLib/Vtk/VtkMappedPropertyVectorTemplate.h
+++ b/MeshLib/Vtk/VtkMappedPropertyVectorTemplate.h
@@ -13,8 +13,7 @@
  *
  */
 
-#ifndef VTKMAPPEDELEMENTDATAARRAY_H_
-#define VTKMAPPEDELEMENTDATAARRAY_H_
+#pragma once
 
 #include <vtkMappedDataArray.h>
 #include <vtkObjectFactory.h>  // for vtkStandardNewMacro
@@ -136,5 +135,3 @@ private:
 } // end namespace MeshLib
 
 #include "VtkMappedPropertyVectorTemplate-impl.h"
-
-#endif // VTKMAPPEDELEMENTDATAARRAY_H_
diff --git a/MeshLib/Vtk/VtkMeshNodalCoordinatesTemplate.h b/MeshLib/Vtk/VtkMeshNodalCoordinatesTemplate.h
index 7cbe8986ac1aacaf05e67f960e3c99c6fc34c120..350736b8f0b20ee31a819e9c7eb6f54fdad9a3b3 100644
--- a/MeshLib/Vtk/VtkMeshNodalCoordinatesTemplate.h
+++ b/MeshLib/Vtk/VtkMeshNodalCoordinatesTemplate.h
@@ -13,8 +13,7 @@
  *
  */
 
-#ifndef VTKMESHNODALCOORDINATES_H_
-#define VTKMESHNODALCOORDINATES_H_
+#pragma once
 
 #include <vtkMappedDataArray.h>
 #include <vtkObjectFactory.h>  // for vtkStandardNewMacro
@@ -134,5 +133,3 @@ private:
 } // end namespace
 
 #include "VtkMeshNodalCoordinatesTemplate-impl.h"
-
-#endif // VTKMESHNODALCOORDINATES_H_
diff --git a/MeshLib/VtkOGSEnum.h b/MeshLib/VtkOGSEnum.h
index 35d754f86260a0dcbec30f4d1f6cbbe7293abf6f..ffe516441d9b1a46cac3de3fe48da1eb102611b4 100644
--- a/MeshLib/VtkOGSEnum.h
+++ b/MeshLib/VtkOGSEnum.h
@@ -7,13 +7,10 @@
  *
  */
 
-#ifndef VTKOGSENUM_H_
-#define VTKOGSENUM_H_
+#pragma once
 
 #include "MeshEnums.h"
 
 MeshLib::CellType VtkCellTypeToOGS(int type);
 
 int OGSToVtkCellType(MeshLib::CellType ogs);
-
-#endif // VTKOGSENUM_H_
diff --git a/MeshLib/convertMeshToGeo.h b/MeshLib/convertMeshToGeo.h
index dc8e595c62e9cef5a25a09aff69279a3787a8766..73923a292cba1b96d48faca9f16d3b4f1fa103dc 100644
--- a/MeshLib/convertMeshToGeo.h
+++ b/MeshLib/convertMeshToGeo.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef CONVERTMESHTOGEO_H_
-#define CONVERTMESHTOGEO_H_
+#pragma once
 
 #include <limits>
 #include <string>
@@ -48,5 +47,3 @@ namespace MeshLib
     MeshLib::Mesh* convertSurfaceToMesh(const GeoLib::Surface &sfc, const std::string &mesh_name, double eps = std::numeric_limits<double>::epsilon());
 
 } // namespace
-
-#endif /* CONVERTMESHTOGEO_H_ */
diff --git a/NumLib/Assembler/SerialExecutor.h b/NumLib/Assembler/SerialExecutor.h
index 1942ca529cd51f71703e0698d1a8e92c796d473d..97755eb72f1f0424cb4fc9a5734fc29a472420b0 100644
--- a/NumLib/Assembler/SerialExecutor.h
+++ b/NumLib/Assembler/SerialExecutor.h
@@ -10,8 +10,7 @@
  *
  */
 
-#ifndef NUMLIB_SERIALEXECUTOR_H_H
-#define NUMLIB_SERIALEXECUTOR_H_H
+#pragma once
 
 namespace NumLib
 {
@@ -128,5 +127,3 @@ struct SerialExecutor
 };
 
 }   // namespace NumLib
-
-#endif  // NUMLIB_SERIALEXECUTOR_H_H
diff --git a/NumLib/DOF/ComponentGlobalIndexDict.h b/NumLib/DOF/ComponentGlobalIndexDict.h
index 0e704b4c86704e0fc7a52afc38ee315227ce4216..e844601c7e2af75f482f33e43485a45cc1cb572a 100644
--- a/NumLib/DOF/ComponentGlobalIndexDict.h
+++ b/NumLib/DOF/ComponentGlobalIndexDict.h
@@ -10,8 +10,7 @@
  *
  */
 
-#ifndef NUMLIB_COMPONENTGLOBALINDEXDICT_H_
-#define NUMLIB_COMPONENTGLOBALINDEXDICT_H_
+#pragma once
 
 #include <limits>
 
@@ -119,5 +118,3 @@ typedef boost::multi_index::multi_index_container<
 
 }    // namespace detail
 }    // namespace NumLib
-
-#endif  // NUMLIB_COMPONENTGLOBALINDEXDICT_H_
diff --git a/NumLib/DOF/ComputeSparsityPattern.h b/NumLib/DOF/ComputeSparsityPattern.h
index 7b3e4cbb01b571ace979df4f04470a1284566429..15599531b619ee79877a2bdcac10739207271d21 100644
--- a/NumLib/DOF/ComputeSparsityPattern.h
+++ b/NumLib/DOF/ComputeSparsityPattern.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_COMPUTESPARSITYPATTERN_H
-#define NUMLIB_COMPUTESPARSITYPATTERN_H
+#pragma once
 
 #include <vector>
 
@@ -34,6 +33,3 @@ class LocalToGlobalIndexMap;
 GlobalSparsityPattern computeSparsityPattern(
     LocalToGlobalIndexMap const& dof_table, MeshLib::Mesh const& mesh);
 }
-
-#endif // NUMLIB_COMPUTESPARSITYPATTERN_H
-
diff --git a/NumLib/DOF/DOFTableUtil.h b/NumLib/DOF/DOFTableUtil.h
index 1fc5ee5ecae273c3c150557971cc8721e57a2578..1e28a3132d53002b66df16a94b8d41fd2e1b2d95 100644
--- a/NumLib/DOF/DOFTableUtil.h
+++ b/NumLib/DOF/DOFTableUtil.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_DOF_DOFTABLEUTIL_H
-#define NUMLIB_DOF_DOFTABLEUTIL_H
+#pragma once
 
 #include "MathLib/LinAlg/LinAlgEnums.h"
 #include "NumLib/DOF/LocalToGlobalIndexMap.h"
@@ -44,5 +43,3 @@ double norm(GlobalVector const& x, unsigned const global_component,
             LocalToGlobalIndexMap const& dof_table, MeshLib::Mesh const& mesh);
 
 }  // namespace NumLib
-
-#endif  // NUMLIB_DOF_DOFTABLEUTIL_H
diff --git a/NumLib/DOF/GlobalMatrixProviders.h b/NumLib/DOF/GlobalMatrixProviders.h
index 377eacb97293ed6a3e97f00a9156d95b8abda1aa..fcde67cae0eec51294fadc1874a7e9f70188b198 100644
--- a/NumLib/DOF/GlobalMatrixProviders.h
+++ b/NumLib/DOF/GlobalMatrixProviders.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_GLOBAL_MATRIX_PROVIDERS
-#define NUMLIB_GLOBAL_MATRIX_PROVIDERS
+#pragma once
 
 #include "MatrixProviderUser.h"
 
@@ -27,5 +26,3 @@ struct GlobalMatrixProvider
 void cleanupGlobalMatrixProviders();
 
 } // MathLib
-
-#endif // NUMLIB_GLOBAL_MATRIX_PROVIDERS
diff --git a/NumLib/DOF/LocalToGlobalIndexMap.h b/NumLib/DOF/LocalToGlobalIndexMap.h
index 4c8b145ffc005631d6da2fd79af963bd75601422..0fe84a9084b213a975c54a1056eaee0449043d25 100644
--- a/NumLib/DOF/LocalToGlobalIndexMap.h
+++ b/NumLib/DOF/LocalToGlobalIndexMap.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_LOCALTOGLOBALINDEXMAP_H_
-#define NUMLIB_LOCALTOGLOBALINDEXMAP_H_
+#pragma once
 
 #ifndef NDEBUG
 #include <iosfwd>
@@ -220,5 +219,3 @@ private:
 };
 
 }   // namespace NumLib
-
-#endif  // NUMLIB_LOCALTOGLOBALINDEXMAP_H_
diff --git a/NumLib/DOF/MatrixProviderUser.h b/NumLib/DOF/MatrixProviderUser.h
index 5f94cba278c9b9d0944ab959c4448fcf6caf51af..945ebedadbb6fd8cb22eaf996fc74ec53c302ad2 100644
--- a/NumLib/DOF/MatrixProviderUser.h
+++ b/NumLib/DOF/MatrixProviderUser.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_MATRIX_PROVIDER_USER_H
-#define NUMLIB_MATRIX_PROVIDER_USER_H
+#pragma once
 
 #include <cstddef>
 
@@ -117,5 +116,3 @@ public:
 };
 
 } // namespace NumLib
-
-#endif // NUMLIB_MATRIX_PROVIDER_USER_H
diff --git a/NumLib/DOF/MeshComponentMap.h b/NumLib/DOF/MeshComponentMap.h
index 5d4e7d6232fa96630f13e12d6f4d44a77e0524b8..465cd3127ff2cd02f6cc285f363a60c604cee0e0 100644
--- a/NumLib/DOF/MeshComponentMap.h
+++ b/NumLib/DOF/MeshComponentMap.h
@@ -10,8 +10,7 @@
  *
  */
 
-#ifndef NUMLIB_MESHCOMPONENTMAP_H_
-#define NUMLIB_MESHCOMPONENTMAP_H_
+#pragma once
 
 #include "ComponentGlobalIndexDict.h"
 
@@ -192,5 +191,3 @@ private:
 };
 
 }   // namespace NumLib
-
-#endif  // NUMLIB_MESHCOMPONENTMAP_H_
diff --git a/NumLib/DOF/SimpleMatrixVectorProvider.h b/NumLib/DOF/SimpleMatrixVectorProvider.h
index 8a4c2f613f8d4a83259d4f9c533fc88afe87cbc3..c288742d2009fb2dbe71f3853169b0f806b66152 100644
--- a/NumLib/DOF/SimpleMatrixVectorProvider.h
+++ b/NumLib/DOF/SimpleMatrixVectorProvider.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_SIMPLE_MATRIX_PROVIDER_H
-#define NUMLIB_SIMPLE_MATRIX_PROVIDER_H
+#pragma once
 
 #include <map>
 #include <memory>
@@ -88,5 +87,3 @@ private:
 
 
 } // namespace NumLib
-
-#endif // NUMLIB_SIMPLE_MATRIX_PROVIDER_H
diff --git a/NumLib/Distribution/Distribution.h b/NumLib/Distribution/Distribution.h
index c9b2d285da4136741fdc76477ef31ce6192708ae..0c38faded6118dfe0aa383b86e0b1da0d7477366 100644
--- a/NumLib/Distribution/Distribution.h
+++ b/NumLib/Distribution/Distribution.h
@@ -7,9 +7,7 @@
  *
  */
 
-
-#ifndef DISTRIBUTION_H_
-#define DISTRIBUTION_H_
+#pragma once
 
 #include <vector>
 
@@ -36,5 +34,3 @@ std::vector<double> generateNodeValueDistribution(
     const std::vector<std::size_t> &vec_node_ids);
 
 } // NumLib
-
-#endif // DISTRIBUTION_H_
diff --git a/NumLib/Extrapolation/ExtrapolatableElement.h b/NumLib/Extrapolation/ExtrapolatableElement.h
index 3a67de03cabed7f5c53dc8b4151b2965616e10ef..1ecfa992af3283dd6f17067e57e560e0699f8d5b 100644
--- a/NumLib/Extrapolation/ExtrapolatableElement.h
+++ b/NumLib/Extrapolation/ExtrapolatableElement.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_EXTRAPOLATION_EXTRAPOLATABLEELEMENT_H
-#define NUMLIB_EXTRAPOLATION_EXTRAPOLATABLEELEMENT_H
+#pragma once
 
 #include <Eigen/Core>
 
@@ -31,5 +30,3 @@ public:
 };
 
 }  // namespace NumLib
-
-#endif  // NUMLIB_EXTRAPOLATION_EXTRAPOLATABLEELEMENT_H
diff --git a/NumLib/Extrapolation/ExtrapolatableElementCollection.h b/NumLib/Extrapolation/ExtrapolatableElementCollection.h
index 7f8a0adeb92c6a19a20e703fa625f357d18b4135..c07d719a79a71a8cfd4e3c7d1bb53f0312c9f582 100644
--- a/NumLib/Extrapolation/ExtrapolatableElementCollection.h
+++ b/NumLib/Extrapolation/ExtrapolatableElementCollection.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_EXTRAPOLATION_EXTRAPOLATABLEELEMENTCOLLECTION_H
-#define NUMLIB_EXTRAPOLATION_EXTRAPOLATABLEELEMENTCOLLECTION_H
+#pragma once
 
 #include <vector>
 #include "ExtrapolatableElement.h"
@@ -131,5 +130,3 @@ makeExtrapolatable(LocalAssemblerCollection const& local_assemblers,
         local_assemblers, integration_point_values_method};
 }
 }  // namespace NumLib
-
-#endif  // NUMLIB_EXTRAPOLATION_EXTRAPOLATABLEELEMENTCOLLECTION_H
diff --git a/NumLib/Extrapolation/Extrapolator.h b/NumLib/Extrapolation/Extrapolator.h
index 58f4ba054147471bf01450c56333acb6e422b0c3..fa13cace48383ba255688c0780dc9673a7c84bf8 100644
--- a/NumLib/Extrapolation/Extrapolator.h
+++ b/NumLib/Extrapolation/Extrapolator.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_EXTRAPOLATOR_H
-#define NUMLIB_EXTRAPOLATOR_H
+#pragma once
 
 #include <vector>
 
@@ -49,5 +48,3 @@ public:
 };
 
 } // namespace ProcessLib
-
-#endif // NUMLIB_EXTRAPOLATOR_H
diff --git a/NumLib/Extrapolation/LocalLinearLeastSquaresExtrapolator.h b/NumLib/Extrapolation/LocalLinearLeastSquaresExtrapolator.h
index ee1981a20434f16140e246ac5c33b48d5b689511..a5f58e2910bc59c252a9e8475fa05cf4e02fb5d0 100644
--- a/NumLib/Extrapolation/LocalLinearLeastSquaresExtrapolator.h
+++ b/NumLib/Extrapolation/LocalLinearLeastSquaresExtrapolator.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_LOCAL_LLSQ_EXTRAPOLATOR_H
-#define NUMLIB_LOCAL_LLSQ_EXTRAPOLATOR_H
+#pragma once
 
 #include <map>
 
@@ -123,5 +122,3 @@ private:
 };
 
 }  // namespace NumLib
-
-#endif  // NUMLIB_LOCAL_LLSQ_EXTRAPOLATOR_H
diff --git a/NumLib/Fem/CoordinatesMapping/NaturalCoordinatesMapping.h b/NumLib/Fem/CoordinatesMapping/NaturalCoordinatesMapping.h
index c4a4e3013cf391aaa4063fa0ada8acf3a28bba26..4da44b51b97021d95045c1d1e33fb236f5f63452 100644
--- a/NumLib/Fem/CoordinatesMapping/NaturalCoordinatesMapping.h
+++ b/NumLib/Fem/CoordinatesMapping/NaturalCoordinatesMapping.h
@@ -10,10 +10,7 @@
  *
  */
 
-
-#ifndef NATURALCOORDINATESMAPPING_H_
-#define NATURALCOORDINATESMAPPING_H_
-
+#pragma once
 
 #include "ShapeMatrices.h"
 
@@ -88,5 +85,3 @@ struct NaturalCoordinatesMapping
 };
 
 } // NumLib
-
-#endif //NATURALCOORDINATESMAPPING_H_
diff --git a/NumLib/Fem/CoordinatesMapping/ShapeMatrices.h b/NumLib/Fem/CoordinatesMapping/ShapeMatrices.h
index 77ff3f79bd5da2a25f90e5f9f77aadb55495880b..a74020f82594ff248a3c78146b0da097c68990db 100644
--- a/NumLib/Fem/CoordinatesMapping/ShapeMatrices.h
+++ b/NumLib/Fem/CoordinatesMapping/ShapeMatrices.h
@@ -10,8 +10,7 @@
  *
  */
 
-#ifndef SHAPEMATRICES_H_
-#define SHAPEMATRICES_H_
+#pragma once
 
 #include <ostream>
 
@@ -110,5 +109,3 @@ struct ShapeMatrices
 } // NumLib
 
 #include "ShapeMatrices-impl.h"
-
-#endif //SHAPEMATRICES_H_
diff --git a/NumLib/Fem/FiniteElement/C0IsoparametricElements.h b/NumLib/Fem/FiniteElement/C0IsoparametricElements.h
index 6ffe766c61ed115c0df7e98c7662fbbd3d951e93..52b865bcec054a5a75c2b897cfc0b2cf425066fb 100644
--- a/NumLib/Fem/FiniteElement/C0IsoparametricElements.h
+++ b/NumLib/Fem/FiniteElement/C0IsoparametricElements.h
@@ -10,9 +10,7 @@
  *
  */
 
-
-#ifndef C0ISOPARAMETRICELEMENTS_H_
-#define C0ISOPARAMETRICELEMENTS_H_
+#pragma once
 
 #include "NumLib/Fem/ShapeFunction/ShapePoint1.h"
 #include "NumLib/Fem/ShapeFunction/ShapeLine2.h"
@@ -133,5 +131,3 @@ struct FePYRA13
 };
 
 } // NumLib
-
-#endif //C0ISOPARAMETRICELEMENTS_H_
diff --git a/NumLib/Fem/FiniteElement/LowerDimShapeTable.h b/NumLib/Fem/FiniteElement/LowerDimShapeTable.h
index e4fa78e9a4fe91f2df02e110100d916217968100..3f5166d370412f874f23faefeff4f1a34b89b2dd 100644
--- a/NumLib/Fem/FiniteElement/LowerDimShapeTable.h
+++ b/NumLib/Fem/FiniteElement/LowerDimShapeTable.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUM_LIB_FEM_FINITE_ELEMENT_LOWERSHAPETABLE_H_
-#define NUM_LIB_FEM_FINITE_ELEMENT_LOWERSHAPETABLE_H_
+#pragma once
 
 #include "NumLib/Fem/ShapeFunction/ShapeHex20.h"
 #include "NumLib/Fem/ShapeFunction/ShapeHex8.h"
@@ -73,5 +72,3 @@ struct LowerDim<NumLib::ShapePyra13>
 };
 
 }  // namespace NumLib
-
-#endif  // NUM_LIB_FEM_FINITE_ELEMENT_LOWERSHAPETABLE_H_
diff --git a/NumLib/Fem/FiniteElement/TemplateIsoparametric.h b/NumLib/Fem/FiniteElement/TemplateIsoparametric.h
index 317021d73367af81bfabe7067d1489a8188d595b..a62e301d3988bd40674c7aad45490856f7162f25 100644
--- a/NumLib/Fem/FiniteElement/TemplateIsoparametric.h
+++ b/NumLib/Fem/FiniteElement/TemplateIsoparametric.h
@@ -10,10 +10,7 @@
  *
  */
 
-
-#ifndef TEMPLATEISOPARAMETRIC_H_
-#define TEMPLATEISOPARAMETRIC_H_
-
+#pragma once
 
 #include <cassert>
 #include <boost/math/constants/constants.hpp>
@@ -152,5 +149,3 @@ private:
 };
 
 } // NumLib
-
-#endif //TEMPLATEISOPARAMETRIC_H_
diff --git a/NumLib/Fem/Integration/GaussIntegrationPolicy.h b/NumLib/Fem/Integration/GaussIntegrationPolicy.h
index 051009599bba862e71f91399c3073b6440ea2a6f..d2cd2d10fb6d8d57f82c1d9f1e4ab7983f9677a1 100644
--- a/NumLib/Fem/Integration/GaussIntegrationPolicy.h
+++ b/NumLib/Fem/Integration/GaussIntegrationPolicy.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_GAUSSINTEGRATIONPOLICY_H_
-#define NUMLIB_GAUSSINTEGRATIONPOLICY_H_
+#pragma once
 
 #include "MeshLib/Elements/Point.h"
 #include "MeshLib/Elements/Tri.h"
@@ -106,5 +105,3 @@ struct GaussIntegrationPolicy<MeshLib::Pyramid13>
 };
 
 }   // namespace NumLib
-
-#endif  // NUMLIB_GAUSSINTEGRATIONPOLICY_H_
diff --git a/NumLib/Fem/Integration/IntegrationGaussPrism.h b/NumLib/Fem/Integration/IntegrationGaussPrism.h
index 5408305ee3476d42cc0450d8b6f3dc1910578d4d..f2fdb573b6f18edb261b0b88f60816525a9f54c8 100644
--- a/NumLib/Fem/Integration/IntegrationGaussPrism.h
+++ b/NumLib/Fem/Integration/IntegrationGaussPrism.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef INTEGRATIONGAUSSPRISM_H_
-#define INTEGRATIONGAUSSPRISM_H_
+#pragma once
 
 #include "MathLib/Integration/GaussLegendre.h"
 #include "MathLib/Integration/GaussLegendreTri.h"
@@ -96,5 +95,3 @@ private:
 };
 
 }
-
-#endif //INTEGRATIONGAUSSPRISM_H_
diff --git a/NumLib/Fem/Integration/IntegrationGaussPyramid.h b/NumLib/Fem/Integration/IntegrationGaussPyramid.h
index 745679e012993ee98949b1f5f2b94bc021e0bffe..d8e0707f47c7503b9c74b0b097335381e3cba7d3 100644
--- a/NumLib/Fem/Integration/IntegrationGaussPyramid.h
+++ b/NumLib/Fem/Integration/IntegrationGaussPyramid.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef INTEGRATIONGAUSSPYRAMID_H_
-#define INTEGRATIONGAUSSPYRAMID_H_
+#pragma once
 
 #include "MathLib/Integration/GaussLegendrePyramid.h"
 
@@ -109,5 +108,3 @@ private:
 };
 
 }
-
-#endif //INTEGRATIONGAUSSPYRAMID_H_
diff --git a/NumLib/Fem/Integration/IntegrationGaussRegular.h b/NumLib/Fem/Integration/IntegrationGaussRegular.h
index 116d992187ec975aef8a3a839cf1835a6c9388f5..750ccf06dd63d815366f570187d3167b563dcab4 100644
--- a/NumLib/Fem/Integration/IntegrationGaussRegular.h
+++ b/NumLib/Fem/Integration/IntegrationGaussRegular.h
@@ -10,8 +10,7 @@
  *
  */
 
-#ifndef INTEGRATIONGAUSSREGULAR_H_
-#define INTEGRATIONGAUSSREGULAR_H_
+#pragma once
 
 #include <cmath>
 #include <array>
@@ -98,5 +97,3 @@ private:
 } // NumLib
 
 #include "IntegrationGaussRegular-impl.h"
-
-#endif //INTEGRATIONGAUSSREGULAR_H_
diff --git a/NumLib/Fem/Integration/IntegrationGaussTet.h b/NumLib/Fem/Integration/IntegrationGaussTet.h
index c8d234af115a9edf85cd0e3de0a769f17018ffb7..29e93014463c5580661f19d71343bd8fe756bf23 100644
--- a/NumLib/Fem/Integration/IntegrationGaussTet.h
+++ b/NumLib/Fem/Integration/IntegrationGaussTet.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef INTEGRATIONGAUSSTET_H_
-#define INTEGRATIONGAUSSTET_H_
+#pragma once
 
 #include "MathLib/Integration/GaussLegendreTet.h"
 
@@ -109,5 +108,3 @@ private:
 };
 
 }
-
-#endif //INTEGRATIONGAUSSTET_H_
diff --git a/NumLib/Fem/Integration/IntegrationGaussTri.h b/NumLib/Fem/Integration/IntegrationGaussTri.h
index 8f59726e1a7192fee836168b53d9461c675da1fd..6d66790dd88db22b1297af49c1d5e2f626db3e52 100644
--- a/NumLib/Fem/Integration/IntegrationGaussTri.h
+++ b/NumLib/Fem/Integration/IntegrationGaussTri.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef INTEGRATIONGAUSSTRI_H_
-#define INTEGRATIONGAUSSTRI_H_
+#pragma once
 
 #include "MathLib/Integration/GaussLegendreTri.h"
 
@@ -125,5 +124,3 @@ private:
 };
 
 }
-
-#endif //INTEGRATIONGAUSSTRI_H_
diff --git a/NumLib/Fem/Integration/IntegrationPoint.h b/NumLib/Fem/Integration/IntegrationPoint.h
index ee639c38f0a0eb4c3c3d350515e352ca6cb5ff00..eaaee68924b0d5271675d6bad3e15e0d8024b54e 100644
--- a/NumLib/Fem/Integration/IntegrationPoint.h
+++ b/NumLib/Fem/Integration/IntegrationPoint.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_INTEGRATIONPOINT_H_
-#define NUMLIB_INTEGRATIONPOINT_H_
+#pragma once
 
 namespace NumLib
 {
@@ -74,5 +73,3 @@ public:
     }
 };
 }
-
-#endif  // NUMLIB_INTEGRATIONPOINT_H_
diff --git a/NumLib/Fem/ShapeFunction/ShapeHex20.h b/NumLib/Fem/ShapeFunction/ShapeHex20.h
index 295099d9e80cdfbb092642ddbfbc8a820b94bd61..bcf4f111cb00573707f8cb2106aa4665fba6c0df 100644
--- a/NumLib/Fem/ShapeFunction/ShapeHex20.h
+++ b/NumLib/Fem/ShapeFunction/ShapeHex20.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef SHAPEHEX20_H_
-#define SHAPEHEX20_H_
+#pragma once
 
 #include "MeshLib/Elements/Hex.h"
 
@@ -48,5 +47,3 @@ public:
 }
 
 #include "ShapeHex20-impl.h"
-
-#endif //SHAPEHEX20_H_
diff --git a/NumLib/Fem/ShapeFunction/ShapeHex8.h b/NumLib/Fem/ShapeFunction/ShapeHex8.h
index 7ff7f3373f8cf79741b63e8582d8dc37416491bc..96ed9b09e5cf9e1db1bbf8b37db1732c13b85e96 100644
--- a/NumLib/Fem/ShapeFunction/ShapeHex8.h
+++ b/NumLib/Fem/ShapeFunction/ShapeHex8.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef SHAPEHEX8_H_
-#define SHAPEHEX8_H_
+#pragma once
 
 #include "MeshLib/Elements/Hex.h"
 
@@ -66,5 +65,3 @@ public:
 }
 
 #include "ShapeHex8-impl.h"
-
-#endif //SHAPEHEX8_H_
diff --git a/NumLib/Fem/ShapeFunction/ShapeLine2.h b/NumLib/Fem/ShapeFunction/ShapeLine2.h
index 8a5b59c181cce037216696965d69887699c6fdb3..738351ec08db30b8de72519ec38e0c96183d7510 100644
--- a/NumLib/Fem/ShapeFunction/ShapeLine2.h
+++ b/NumLib/Fem/ShapeFunction/ShapeLine2.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef SHAPELINE2_H_
-#define SHAPELINE2_H_
+#pragma once
 
 #include "MeshLib/Elements/Line.h"
 
@@ -52,5 +51,3 @@ public:
 }
 
 #include "ShapeLine2-impl.h"
-
-#endif //SHAPELINE2_H_
diff --git a/NumLib/Fem/ShapeFunction/ShapeLine3.h b/NumLib/Fem/ShapeFunction/ShapeLine3.h
index 63f0cd7d3495b65741924f232a877cffe9ec83f0..2633edd744c37291c946b5b13e26edadbfd8b0d7 100644
--- a/NumLib/Fem/ShapeFunction/ShapeLine3.h
+++ b/NumLib/Fem/ShapeFunction/ShapeLine3.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef SHAPELINE3_H_
-#define SHAPELINE3_H_
+#pragma once
 
 #include "MeshLib/Elements/Line.h"
 
@@ -47,5 +46,3 @@ public:
 }
 
 #include "ShapeLine3-impl.h"
-
-#endif //SHAPELINE3_H_
diff --git a/NumLib/Fem/ShapeFunction/ShapePoint1.h b/NumLib/Fem/ShapeFunction/ShapePoint1.h
index b7bc9c239af977a270d20aff7424db1c821ea700..fec749f9e45ced65395ebf2af3cbe2f2d112574d 100644
--- a/NumLib/Fem/ShapeFunction/ShapePoint1.h
+++ b/NumLib/Fem/ShapeFunction/ShapePoint1.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef SHAPEPOINT1_H_
-#define SHAPEPOINT1_H_
+#pragma once
 
 #include "MeshLib/Elements/Point.h"
 
@@ -32,5 +31,3 @@ public:
 }
 
 #include "ShapePoint1-impl.h"
-
-#endif  // SHAPEPOINT1_H_
diff --git a/NumLib/Fem/ShapeFunction/ShapePrism15.h b/NumLib/Fem/ShapeFunction/ShapePrism15.h
index 148e663d3459e495920c8fc8321ade24566a63b5..8be25e633dce9dbeded643c0e35b7614b3193887 100644
--- a/NumLib/Fem/ShapeFunction/ShapePrism15.h
+++ b/NumLib/Fem/ShapeFunction/ShapePrism15.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef SHAPEPRISM15_H_
-#define SHAPEPRISM15_H_
+#pragma once
 
 #include "MeshLib/Elements/Prism.h"
 
@@ -48,5 +47,3 @@ public:
 }
 
 #include "ShapePrism15-impl.h"
-
-#endif //SHAPEPRISM15_H_
diff --git a/NumLib/Fem/ShapeFunction/ShapePrism6.h b/NumLib/Fem/ShapeFunction/ShapePrism6.h
index 0343ed667d5a867454610ba3a2d75b75a54692c6..06e53967ae1f4ab545e21af634394f1ed6203d14 100644
--- a/NumLib/Fem/ShapeFunction/ShapePrism6.h
+++ b/NumLib/Fem/ShapeFunction/ShapePrism6.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef SHAPEPRISM6_H_
-#define SHAPEPRISM6_H_
+#pragma once
 
 #include "MeshLib/Elements/Prism.h"
 
@@ -48,5 +47,3 @@ public:
 }
 
 #include "ShapePrism6-impl.h"
-
-#endif //SHAPEPRISM6_H_
diff --git a/NumLib/Fem/ShapeFunction/ShapePyra13.h b/NumLib/Fem/ShapeFunction/ShapePyra13.h
index 57a2519ef1362fb88b3dceb70d48e94514b0101b..e3092de9637fec24fa0da5dd44528defa9c54a4a 100644
--- a/NumLib/Fem/ShapeFunction/ShapePyra13.h
+++ b/NumLib/Fem/ShapeFunction/ShapePyra13.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef SHAPEPYRA13_H_
-#define SHAPEPYRA13_H_
+#pragma once
 
 #include "MeshLib/Elements/Pyramid.h"
 
@@ -48,5 +47,3 @@ public:
 }
 
 #include "ShapePyra13-impl.h"
-
-#endif //SHAPEPYRA13_H_
diff --git a/NumLib/Fem/ShapeFunction/ShapePyra5.h b/NumLib/Fem/ShapeFunction/ShapePyra5.h
index cc0f6c882f649e8b49e831d68c746a3976d61187..7c7c1ba5c74fe37cba924a69017532fafe6c73d5 100644
--- a/NumLib/Fem/ShapeFunction/ShapePyra5.h
+++ b/NumLib/Fem/ShapeFunction/ShapePyra5.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef SHAPEPYRA5_H_
-#define SHAPEPYRA5_H_
+#pragma once
 
 #include "MeshLib/Elements/Pyramid.h"
 
@@ -48,5 +47,3 @@ public:
 }
 
 #include "ShapePyra5-impl.h"
-
-#endif //SHAPEPYRA5_H_
diff --git a/NumLib/Fem/ShapeFunction/ShapeQuad4.h b/NumLib/Fem/ShapeFunction/ShapeQuad4.h
index fda3408783c84dfe5733a5c3a86310a221618457..c904fffcaa570da673ebde9f709f73fa73aa2ce5 100644
--- a/NumLib/Fem/ShapeFunction/ShapeQuad4.h
+++ b/NumLib/Fem/ShapeFunction/ShapeQuad4.h
@@ -10,8 +10,7 @@
  *
  */
 
-#ifndef SHAPEQUAD4_H_
-#define SHAPEQUAD4_H_
+#pragma once
 
 #include "MeshLib/Elements/Quad.h"
 
@@ -60,5 +59,3 @@ public:
 }
 
 #include "ShapeQuad4-impl.h"
-
-#endif //SHAPEQUAD4_H_
diff --git a/NumLib/Fem/ShapeFunction/ShapeQuad8.h b/NumLib/Fem/ShapeFunction/ShapeQuad8.h
index 10c54957ff60ddd20c353e8aaa0e2dc982626e18..01a5a8a56abc45f7004c512d873f36f7bfaa09ea 100644
--- a/NumLib/Fem/ShapeFunction/ShapeQuad8.h
+++ b/NumLib/Fem/ShapeFunction/ShapeQuad8.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef SHAPEQUAD8_H_
-#define SHAPEQUAD8_H_
+#pragma once
 
 #include "MeshLib/Elements/Quad.h"
 
@@ -47,5 +46,3 @@ public:
 }
 
 #include "ShapeQuad8-impl.h"
-
-#endif //SHAPEQUAD8_H_
diff --git a/NumLib/Fem/ShapeFunction/ShapeQuad9.h b/NumLib/Fem/ShapeFunction/ShapeQuad9.h
index 93e00191d4d521f66433b5302cbfccfcac1cfd0f..9140f1e27d389bc3341d176e0e6abfb1b779a274 100644
--- a/NumLib/Fem/ShapeFunction/ShapeQuad9.h
+++ b/NumLib/Fem/ShapeFunction/ShapeQuad9.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef SHAPEQUAD9_H_
-#define SHAPEQUAD9_H_
+#pragma once
 
 #include "MeshLib/Elements/Quad.h"
 
@@ -47,5 +46,3 @@ public:
 }
 
 #include "ShapeQuad9-impl.h"
-
-#endif //SHAPEQUAD9_H_
diff --git a/NumLib/Fem/ShapeFunction/ShapeTet10.h b/NumLib/Fem/ShapeFunction/ShapeTet10.h
index b93f52d75f539158de41e70a2b44a7a686e64ead..7c9a7ceab50e59b378338576d36f7f943fa76607 100644
--- a/NumLib/Fem/ShapeFunction/ShapeTet10.h
+++ b/NumLib/Fem/ShapeFunction/ShapeTet10.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef SHAPETET10_H_
-#define SHAPETET10_H_
+#pragma once
 
 #include "MeshLib/Elements/Tet.h"
 
@@ -48,5 +47,3 @@ public:
 }
 
 #include "ShapeTet10-impl.h"
-
-#endif //SHAPETET10_H_
diff --git a/NumLib/Fem/ShapeFunction/ShapeTet4.h b/NumLib/Fem/ShapeFunction/ShapeTet4.h
index e505cdbae3d8b9200c4e179b2f9dc042aa26739b..65039e06ff38a3fb0e9413bd0d857049679fc215 100644
--- a/NumLib/Fem/ShapeFunction/ShapeTet4.h
+++ b/NumLib/Fem/ShapeFunction/ShapeTet4.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef SHAPETET4_H_
-#define SHAPETET4_H_
+#pragma once
 
 #include "MeshLib/Elements/Tet.h"
 
@@ -48,5 +47,3 @@ public:
 }
 
 #include "ShapeTet4-impl.h"
-
-#endif //SHAPETET4_H_
diff --git a/NumLib/Fem/ShapeFunction/ShapeTri3.h b/NumLib/Fem/ShapeFunction/ShapeTri3.h
index c0291641b2c5a2e56ab16c453ba8c128b900be4d..1e85878ead17e9fa593ddbbfe4ab44b80fac6881 100644
--- a/NumLib/Fem/ShapeFunction/ShapeTri3.h
+++ b/NumLib/Fem/ShapeFunction/ShapeTri3.h
@@ -12,8 +12,7 @@
  *
  */
 
-#ifndef SHAPETRI3_H_
-#define SHAPETRI3_H_
+#pragma once
 
 #include "MeshLib/Elements/Tri.h"
 
@@ -61,5 +60,3 @@ public:
 }
 
 #include "ShapeTri3-impl.h"
-
-#endif //SHAPETRI3_H_
diff --git a/NumLib/Fem/ShapeFunction/ShapeTri6.h b/NumLib/Fem/ShapeFunction/ShapeTri6.h
index aa0eafd49c1bb27096999a0ef1c2cc9d0b8e687a..c3d7e67b0c8c0b3d29dcdacb0cdda7292fb6ee56 100644
--- a/NumLib/Fem/ShapeFunction/ShapeTri6.h
+++ b/NumLib/Fem/ShapeFunction/ShapeTri6.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef SHAPETRI6_H_
-#define SHAPETRI6_H_
+#pragma once
 
 #include "MeshLib/Elements/Tri.h"
 
@@ -49,5 +48,3 @@ public:
 }
 
 #include "ShapeTri6-impl.h"
-
-#endif //SHAPETRI6_H_
diff --git a/NumLib/Fem/ShapeMatrixPolicy.h b/NumLib/Fem/ShapeMatrixPolicy.h
index b9222e662ed64f931ca537c92af646ccca23998f..3fe0eda74483df3126f1a2b91738d5c3747f4ffe 100644
--- a/NumLib/Fem/ShapeMatrixPolicy.h
+++ b/NumLib/Fem/ShapeMatrixPolicy.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef SHAPE_MATRIX_POLICY_H_
-#define SHAPE_MATRIX_POLICY_H_
+#pragma once
 
 #include "NumLib/Fem/CoordinatesMapping/ShapeMatrices.h"
 
@@ -132,5 +131,3 @@ const unsigned OGS_EIGEN_DYNAMIC_SHAPE_MATRICES_FLAG = 0;
 
 //static_assert(std::is_class<ShapeMatrixPolicyType<>::value,
         //"ShapeMatrixPolicyType was not defined.");
-
-#endif  // SHAPE_MATRIX_POLICY_H_
diff --git a/NumLib/Function/ISpatialFunction.h b/NumLib/Function/ISpatialFunction.h
index fc92a01f189bc5514a7a1879d94bca5de36d10f2..0d3b37ab76b31c7c5216e3085cbc4f637d261d0a 100644
--- a/NumLib/Function/ISpatialFunction.h
+++ b/NumLib/Function/ISpatialFunction.h
@@ -10,9 +10,7 @@
  *
  */
 
-
-#ifndef ISPATIALFUNCTION_H_
-#define ISPATIALFUNCTION_H_
+#pragma once
 
 #include <vector>
 
@@ -38,5 +36,3 @@ public:
 };
 
 } // NumLib
-
-#endif //ISPATIALFUNCTION_H_
diff --git a/NumLib/Function/Interpolation.h b/NumLib/Function/Interpolation.h
index 530a56479941af08365b48bf2ef0b66a3f2a19fe..74955437c455c2426cad8287404ae0a3e65f6d18 100644
--- a/NumLib/Function/Interpolation.h
+++ b/NumLib/Function/Interpolation.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_INTERPOLATION_H
-#define NUMLIB_INTERPOLATION_H
+#pragma once
 
 #include<array>
 #include<cassert>
@@ -86,5 +85,3 @@ void shapeFunctionInterpolate(
 }
 
 } // namespace NumLib
-
-#endif // NUMLIB_INTERPOLATION_H
diff --git a/NumLib/Function/LinearInterpolationAlongPolyline.h b/NumLib/Function/LinearInterpolationAlongPolyline.h
index e710b39438cab9a5112f43d01262917ab1f5b511..1e214df96f6fcc9329e2ad3c78dcb87e499c2616 100644
--- a/NumLib/Function/LinearInterpolationAlongPolyline.h
+++ b/NumLib/Function/LinearInterpolationAlongPolyline.h
@@ -10,8 +10,7 @@
  *
  */
 
-#ifndef LINEARINTERPOLATIONALONGPOLYLINE_H_
-#define LINEARINTERPOLATIONALONGPOLYLINE_H_
+#pragma once
 
 #include <vector>
 
@@ -77,6 +76,3 @@ private:
 };
 
 } // NumLib
-
-#endif //LINEARINTERPOLATIONALONGPOLYLINE_H_
-
diff --git a/NumLib/Function/LinearInterpolationOnSurface.h b/NumLib/Function/LinearInterpolationOnSurface.h
index 453612c3e5caabf2277fc85c27b71a4c9e5d7f2f..6529d273985fcddfde59937b39d24ad9de2d1df0 100644
--- a/NumLib/Function/LinearInterpolationOnSurface.h
+++ b/NumLib/Function/LinearInterpolationOnSurface.h
@@ -10,8 +10,7 @@
  *
  */
 
-#ifndef LINEARINTERPOLATIONSURFACE_H_
-#define LINEARINTERPOLATIONSURFACE_H_
+#pragma once
 
 #include <vector>
 
@@ -96,6 +95,3 @@ private:
 };
 
 } // NumLib
-
-#endif //LINEARINTERPOLATIONSURFACE_H_
-
diff --git a/NumLib/Function/SpatialFunctionLinear.h b/NumLib/Function/SpatialFunctionLinear.h
index a1393f702061ea9ba0baa9a9359b9aa462e028ea..d8975b58b972149dec0abf73dac0ddf47b55e381 100644
--- a/NumLib/Function/SpatialFunctionLinear.h
+++ b/NumLib/Function/SpatialFunctionLinear.h
@@ -10,8 +10,7 @@
  *
  */
 
-#ifndef SPATIALFUNCTIONLINEAR_H_
-#define SPATIALFUNCTIONLINEAR_H_
+#pragma once
 
 #include "MathLib/LinearFunction.h"
 #include "TemplateSpatialFunction.h"
@@ -23,5 +22,3 @@ namespace NumLib
 typedef TemplateSpatialFunction<MathLib::LinearFunction<double, 3> > SpatialFunctionLinear;
 
 }
-
-#endif /* SPATIALFUNCTIONLINEAR_H_ */
diff --git a/NumLib/Function/TemplateSpatialFunction.h b/NumLib/Function/TemplateSpatialFunction.h
index 109447ea525e009c909a37837eb91f897a4a79ca..8b372e1d64330cb2bcd3a1c8ce984e80896cae9a 100644
--- a/NumLib/Function/TemplateSpatialFunction.h
+++ b/NumLib/Function/TemplateSpatialFunction.h
@@ -10,8 +10,7 @@
  *
  */
 
-#ifndef TEMPLATESPATIALFUNCTION_H_
-#define TEMPLATESPATIALFUNCTION_H_
+#pragma once
 
 #include "ISpatialFunction.h"
 
@@ -50,5 +49,3 @@ private:
 };
 
 }
-
-#endif /* TEMPLATESPATIALFUNCTION_H_ */
diff --git a/NumLib/IndexValueVector.h b/NumLib/IndexValueVector.h
index 4dd248418e2e3aaf0770f1b894135803c3a33178..713c1c1eb2c3839f3f0ccd74b3df197e80a9dcda 100644
--- a/NumLib/IndexValueVector.h
+++ b/NumLib/IndexValueVector.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUM_LIB_INDEXVALUEVECTOR_H
-#define NUM_LIB_INDEXVALUEVECTOR_H
+#pragma once
 
 #include <vector>
 
@@ -23,5 +22,3 @@ struct IndexValueVector final
 };
 
 }
-
-#endif  // NUM_LIB_INDEXVALUEVECTOR_H
diff --git a/NumLib/NamedFunction.h b/NumLib/NamedFunction.h
index 1baa71c8e50caa035be062dc68b1ffa82e0f2fff..bea46bac736816048215cd8e63b55f50940f2e1a 100644
--- a/NumLib/NamedFunction.h
+++ b/NumLib/NamedFunction.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_NAMED_FUNCTION
-#define NUMLIB_NAMED_FUNCTION
+#pragma once
 
 #include <cassert>
 #include <functional>
@@ -112,5 +111,3 @@ NamedFunction::NamedFunction(std::string const& name,
 }
 
 }  // namespace NumLib
-
-#endif // NUMLIB_NAMED_FUNCTION
diff --git a/NumLib/NamedFunctionCaller.h b/NumLib/NamedFunctionCaller.h
index cef93d179d9fade3d49f2733b8ae9823801b22a9..425c17ab4cc05724435f804bd86ef3ddeae8dc2d 100644
--- a/NumLib/NamedFunctionCaller.h
+++ b/NumLib/NamedFunctionCaller.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_NAMEDFUNCTIONCALLER_H
-#define NUMLIB_NAMEDFUNCTIONCALLER_H
+#pragma once
 
 #include <map>
 #include <vector>
@@ -124,7 +123,3 @@ private:
 };
 
 } // namespace NumLib
-
-
-
-#endif // NUMLIB_NAMEDFUNCTIONCALLER_H
diff --git a/NumLib/NamedFunctionProvider.h b/NumLib/NamedFunctionProvider.h
index 7263b9af70846b0738b0e47c60cdacc1badf9761..bdb59ddc67b75e4a079fd6710e1a91ba39d4b80f 100644
--- a/NumLib/NamedFunctionProvider.h
+++ b/NumLib/NamedFunctionProvider.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_NAMEDFUNCTIONPROVIDER_H
-#define NUMLIB_NAMEDFUNCTIONPROVIDER_H
+#pragma once
 
 #include "NamedFunction.h"
 
@@ -28,5 +27,3 @@ public:
 };
 
 } // namespace NumLib
-
-#endif // NUMLIB_NAMEDFUNCTIONPROVIDER_H
diff --git a/NumLib/NewtonRaphson.h b/NumLib/NewtonRaphson.h
index ad4fb7c3b2c24543373ff7b7d4ffc69b84f35049..87af6ee87699258a073902987f4548a923df1231 100644
--- a/NumLib/NewtonRaphson.h
+++ b/NumLib/NewtonRaphson.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_NEWTONRAPHSON_H_
-#define NUMLIB_NEWTONRAPHSON_H_
+#pragma once
 
 #include <boost/optional.hpp>
 #include <logog/include/logog.hpp>
@@ -91,5 +90,3 @@ private:
     const double _tolerance_squared;
 };
 }  // namespace NumLib
-
-#endif  // NUMLIB_NEWTONRAPHSON_H_
diff --git a/NumLib/NumericsConfig.h b/NumLib/NumericsConfig.h
index 7d262f047ae1a92b282db4f41558b8f6da1bfc36..da27bca6974166af9405b6038465d48366d13864 100644
--- a/NumLib/NumericsConfig.h
+++ b/NumLib/NumericsConfig.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_NUMERICSCONFIG_H_
-#define NUMLIB_NUMERICSCONFIG_H_
+#pragma once
 
 /**
  * This file provides a configuration of the global matrix/vector and
@@ -22,7 +21,3 @@
 //
 #include "NumLib/Assembler/SerialExecutor.h"
 using GlobalExecutor = NumLib::SerialExecutor;
-
-
-
-#endif  // NUMLIB_NUMERICSCONFIG_H_
diff --git a/NumLib/ODESolver/ConvergenceCriterion.h b/NumLib/ODESolver/ConvergenceCriterion.h
index 27240c8326bc460dbc7cc90babdfa90646e9819d..dc9faa5a6de909c37b9b235f32a6538909775702 100644
--- a/NumLib/ODESolver/ConvergenceCriterion.h
+++ b/NumLib/ODESolver/ConvergenceCriterion.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_CONVERGENCECRITERION_H
-#define NUMLIB_CONVERGENCECRITERION_H
+#pragma once
 
 #include <memory>
 #include "NumLib/NumericsConfig.h"
@@ -88,5 +87,3 @@ bool checkRelativeTolerance(double const reltol,
                             double const denominator);
 
 } // namespace NumLib
-
-#endif  // NUMLIB_CONVERGENCECRITERION_H
diff --git a/NumLib/ODESolver/ConvergenceCriterionDeltaX.h b/NumLib/ODESolver/ConvergenceCriterionDeltaX.h
index 89522995b8ec06b10104adb754a8d7ace3374f31..36fcb9380ef86e8d1f3dd50b4cd3fdfd23081757 100644
--- a/NumLib/ODESolver/ConvergenceCriterionDeltaX.h
+++ b/NumLib/ODESolver/ConvergenceCriterionDeltaX.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_CONVERGENCECRITERIONDELTAX_H
-#define NUMLIB_CONVERGENCECRITERIONDELTAX_H
+#pragma once
 
 #include <boost/optional.hpp>
 #include "ConvergenceCriterion.h"
@@ -50,5 +49,3 @@ std::unique_ptr<ConvergenceCriterionDeltaX> createConvergenceCriterionDeltaX(
     BaseLib::ConfigTree const& config);
 
 }  // NumLib
-
-#endif  // NUMLIB_CONVERGENCECRITERIONDELTAX_H
diff --git a/NumLib/ODESolver/ConvergenceCriterionPerComponent.h b/NumLib/ODESolver/ConvergenceCriterionPerComponent.h
index 19b30718f9c52176de3d2f4eb1a9e8b93777749f..0ff42fdebf1c5c6f302110ce0df9158242e64f90 100644
--- a/NumLib/ODESolver/ConvergenceCriterionPerComponent.h
+++ b/NumLib/ODESolver/ConvergenceCriterionPerComponent.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_CONVERGENCECRITERIONPERCOMPONENT_H
-#define NUMLIB_CONVERGENCECRITERIONPERCOMPONENT_H
+#pragma once
 
 #include "ConvergenceCriterion.h"
 
@@ -33,5 +32,3 @@ public:
 };
 
 }  // namespace NumLib
-
-#endif  // NUMLIB_CONVERGENCECRITERIONPERCOMPONENT_H
diff --git a/NumLib/ODESolver/ConvergenceCriterionPerComponentDeltaX.h b/NumLib/ODESolver/ConvergenceCriterionPerComponentDeltaX.h
index cb5eae19e5d23d98290d4882b0e2cb1434663083..07edfb4b084a74e594cb31bf7d04776dd637dd97 100644
--- a/NumLib/ODESolver/ConvergenceCriterionPerComponentDeltaX.h
+++ b/NumLib/ODESolver/ConvergenceCriterionPerComponentDeltaX.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_CONVERGENCECRITERIONPERCOMPONENTDELTAX_H
-#define NUMLIB_CONVERGENCECRITERIONPERCOMPONENTDELTAX_H
+#pragma once
 
 #include "MathLib/LinAlg/LinAlgEnums.h"
 #include "ConvergenceCriterionPerComponent.h"
@@ -58,5 +57,3 @@ std::unique_ptr<ConvergenceCriterionPerComponentDeltaX>
 createConvergenceCriterionPerComponentDeltaX(BaseLib::ConfigTree const& config);
 
 }  // namespace NumLib
-
-#endif  // NUMLIB_CONVERGENCECRITERIONPERCOMPONENTDELTAX_H
diff --git a/NumLib/ODESolver/ConvergenceCriterionPerComponentResidual.h b/NumLib/ODESolver/ConvergenceCriterionPerComponentResidual.h
index 2656cfca7b7398b285b1764fbb38722328191e28..a20a6886a7161184366699289586c05873ec3c25 100644
--- a/NumLib/ODESolver/ConvergenceCriterionPerComponentResidual.h
+++ b/NumLib/ODESolver/ConvergenceCriterionPerComponentResidual.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_CONVERGENCECRITERIONPERCOMPONENTRESIDUAL_H
-#define NUMLIB_CONVERGENCECRITERIONPERCOMPONENTRESIDUAL_H
+#pragma once
 
 #include <vector>
 #include "MathLib/LinAlg/LinAlgEnums.h"
@@ -65,5 +64,3 @@ createConvergenceCriterionPerComponentResidual(
     BaseLib::ConfigTree const& config);
 
 }  // namespace NumLib
-
-#endif  // NUMLIB_CONVERGENCECRITERIONPERCOMPONENTRESIDUAL_H
diff --git a/NumLib/ODESolver/ConvergenceCriterionResidual.h b/NumLib/ODESolver/ConvergenceCriterionResidual.h
index accf03cdbe1f2d9e1f82162f66072682eb0be90e..21b793f589d60964aacf32002c4ab1434fd74852 100644
--- a/NumLib/ODESolver/ConvergenceCriterionResidual.h
+++ b/NumLib/ODESolver/ConvergenceCriterionResidual.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_CONVERGENCECRITERIONRESIDUAL_H
-#define NUMLIB_CONVERGENCECRITERIONRESIDUAL_H
+#pragma once
 
 #include <boost/optional.hpp>
 #include "ConvergenceCriterion.h"
@@ -55,5 +54,3 @@ std::unique_ptr<ConvergenceCriterionResidual> createConvergenceCriterionResidual
     BaseLib::ConfigTree const& config);
 
 }  // NumLib
-
-#endif  // NUMLIB_CONVERGENCECRITERIONRESIDUAL_H
diff --git a/NumLib/ODESolver/EquationSystem.h b/NumLib/ODESolver/EquationSystem.h
index dbdeaa4444973bd959e57f3a89d7d8676546c1c3..ba7bbcb74d0b0703b11bdd787514ba73483cd8ac 100644
--- a/NumLib/ODESolver/EquationSystem.h
+++ b/NumLib/ODESolver/EquationSystem.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_EQUATIONSYSTEM_H
-#define NUMLIB_EQUATIONSYSTEM_H
+#pragma once
 
 #include "NumLib/DOF/MatrixProviderUser.h"
 
@@ -66,5 +65,3 @@ public:
 
 //! @}
 }
-
-#endif
diff --git a/NumLib/ODESolver/MatrixTranslator.h b/NumLib/ODESolver/MatrixTranslator.h
index 6960f904d336f5e8dbb86592ab96c4453ffd83d9..f4edf65943bf5aa0acfd6749b24ebefbdee25ec2 100644
--- a/NumLib/ODESolver/MatrixTranslator.h
+++ b/NumLib/ODESolver/MatrixTranslator.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_MATRIXTRANSLATOR_H
-#define NUMLIB_MATRIXTRANSLATOR_H
+#pragma once
 
 #include <memory>
 
@@ -313,5 +312,3 @@ std::unique_ptr<MatrixTranslator<ODETag>> createMatrixTranslator(
 
 //! @}
 }
-
-#endif  // NUMLIB_MATRIXTRANSLATOR_H
diff --git a/NumLib/ODESolver/NonlinearSolver.h b/NumLib/ODESolver/NonlinearSolver.h
index 2a135ce101ec9d1e0399f7bb364db81a76b6218b..c4a9be12b977a547f642c4f192078e1c73697c5d 100644
--- a/NumLib/ODESolver/NonlinearSolver.h
+++ b/NumLib/ODESolver/NonlinearSolver.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_NONLINEARSOLVER_H
-#define NUMLIB_NONLINEARSOLVER_H
+#pragma once
 
 #include <memory>
 #include <utility>
@@ -195,5 +194,3 @@ createNonlinearSolver(
 //! @}
 
 }  // namespace NumLib
-
-#endif  // NUMLIB_NONLINEARSOLVER_H
diff --git a/NumLib/ODESolver/NonlinearSystem.h b/NumLib/ODESolver/NonlinearSystem.h
index dcb38e368050750c9329c8988c7289c7f7e614dc..edfa53160ee62e5dcfc6ea7630cf06fe40813610 100644
--- a/NumLib/ODESolver/NonlinearSystem.h
+++ b/NumLib/ODESolver/NonlinearSystem.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_NONLINEARSYSTEM_H
-#define NUMLIB_NONLINEARSYSTEM_H
+#pragma once
 
 #include "EquationSystem.h"
 #include "Types.h"
@@ -97,5 +96,3 @@ public:
 
 //! @}
 }
-
-#endif  // NUMLIB_NONLINEARSYSTEM_H
diff --git a/NumLib/ODESolver/ODESystem.h b/NumLib/ODESolver/ODESystem.h
index 0a152879f55c8863991f4e2430cfd67baac2120e..aafe142c7a5fbc6caca1b9e48aa95ec45177e868 100644
--- a/NumLib/ODESolver/ODESystem.h
+++ b/NumLib/ODESolver/ODESystem.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_ODESYSTEM_H
-#define NUMLIB_ODESYSTEM_H
+#pragma once
 
 #include "MathLib/LinAlg/MatrixVectorTraits.h"
 #include "NumLib/IndexValueVector.h"
@@ -121,5 +120,3 @@ public:
 
 //! @}
 }
-
-#endif  // NUMLIB_ODESYSTEM_H
diff --git a/NumLib/ODESolver/TimeDiscretization.h b/NumLib/ODESolver/TimeDiscretization.h
index 354e980ca9cf9526f5733eefaaabf2b9bb6d05d3..ea6dd2ec6b641dba25dd623a56cfaabfcef434fd 100644
--- a/NumLib/ODESolver/TimeDiscretization.h
+++ b/NumLib/ODESolver/TimeDiscretization.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_TIMEDISCRETIZATION_H
-#define NUMLIB_TIMEDISCRETIZATION_H
+#pragma once
 
 #include <vector>
 
@@ -501,5 +500,3 @@ private:
 
 //! @}
 }
-
-#endif  // NUMLIB_TIMEDISCRETIZATION_H
diff --git a/NumLib/ODESolver/TimeDiscretizationBuilder.h b/NumLib/ODESolver/TimeDiscretizationBuilder.h
index 27b2d4bced2ab25f995d3cf9871c47cd497df188..9a34d1a49f5233ecd847e24a018c4b6aeec52fdb 100644
--- a/NumLib/ODESolver/TimeDiscretizationBuilder.h
+++ b/NumLib/ODESolver/TimeDiscretizationBuilder.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_TIMEDISCRETIZATION_BUILDER_H
-#define NUMLIB_TIMEDISCRETIZATION_BUILDER_H
+#pragma once
 
 #include <memory>
 
@@ -21,5 +20,3 @@ namespace NumLib
 std::unique_ptr<TimeDiscretization> createTimeDiscretization(
     BaseLib::ConfigTree const& config);
 }
-
-#endif  // NUMLIB_TIMEDISCRETIZATION_BUILDER_H
diff --git a/NumLib/ODESolver/TimeDiscretizedODESystem.h b/NumLib/ODESolver/TimeDiscretizedODESystem.h
index 0e80a99a48bdf6e45adc0e4b8151d3a32dafa8bc..4a9856d08473d38f6118d82da0445116c95b4e76 100644
--- a/NumLib/ODESolver/TimeDiscretizedODESystem.h
+++ b/NumLib/ODESolver/TimeDiscretizedODESystem.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_TIMEDISCRETIZEDODESYSTEM_H
-#define NUMLIB_TIMEDISCRETIZEDODESYSTEM_H
+#pragma once
 
 #include <memory>
 
@@ -234,5 +233,3 @@ private:
 
 //! @}
 }
-
-#endif  // NUMLIB_TIMEDISCRETIZEDODESYSTEM_H
diff --git a/NumLib/ODESolver/TimeLoopSingleODE.h b/NumLib/ODESolver/TimeLoopSingleODE.h
index ae860986c0da68f59e6ab4c10c95c330ef989e46..f07da8a20761bffe2b230ca38dd730e208fb0ede 100644
--- a/NumLib/ODESolver/TimeLoopSingleODE.h
+++ b/NumLib/ODESolver/TimeLoopSingleODE.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_TIMELOOP_H
-#define NUMLIB_TIMELOOP_H
+#pragma once
 
 #include "NumLib/DOF/GlobalMatrixProviders.h"
 #include "TimeDiscretizedODESystem.h"
@@ -134,5 +133,3 @@ bool TimeLoopSingleODE<NLTag>::loop(const double t0, GlobalVector const& x0,
     return nl_slv_succeeded;
 }
 }
-
-#endif  // NUMLIB_TIMELOOP_H
diff --git a/NumLib/ODESolver/Types.h b/NumLib/ODESolver/Types.h
index f0d58a6f8221419c017a1da6f172c7bfe4121e3c..cba55701b6acbb36a4c3ab86fba2adb2ce19519f 100644
--- a/NumLib/ODESolver/Types.h
+++ b/NumLib/ODESolver/Types.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef NUMLIB_TYPES_H
-#define NUMLIB_TYPES_H
+#pragma once
 
 namespace NumLib
 {
@@ -38,5 +37,3 @@ enum class ODESystemTag : char
 //! @}
 
 } // namespace NumLib
-
-#endif // NUMLIB_TYPES_H
diff --git a/NumLib/TimeStepping/Algorithms/FixedTimeStepping.h b/NumLib/TimeStepping/Algorithms/FixedTimeStepping.h
index 851ecc1e5203e7fe775ee6860a1607148b149aa2..af57f4f9ddb65137060d2ece618019513101ea81 100644
--- a/NumLib/TimeStepping/Algorithms/FixedTimeStepping.h
+++ b/NumLib/TimeStepping/Algorithms/FixedTimeStepping.h
@@ -9,8 +9,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef FIXEDTIMESTEPPING_H_
-#define FIXEDTIMESTEPPING_H_
+#pragma once
 
 #include <memory>
 #include <vector>
@@ -99,5 +98,3 @@ private:
 };
 
 } //NumLib
-
-#endif // FIXEDTIMESTEPPING_H_
diff --git a/NumLib/TimeStepping/Algorithms/ITimeStepAlgorithm.h b/NumLib/TimeStepping/Algorithms/ITimeStepAlgorithm.h
index a2572df228709c5270a26882e0645b605926f074..110aa331a5ce8ec08a7b7f4f8a2150a3eab3f7a4 100644
--- a/NumLib/TimeStepping/Algorithms/ITimeStepAlgorithm.h
+++ b/NumLib/TimeStepping/Algorithms/ITimeStepAlgorithm.h
@@ -9,8 +9,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef ITIMESTEPALGORITHM_H_
-#define ITIMESTEPALGORITHM_H_
+#pragma once
 
 #include <vector>
 
@@ -49,5 +48,3 @@ public:
 };
 
 } //NumLib
-
-#endif //ITIMESTEPALGORITHM_H_
diff --git a/NumLib/TimeStepping/Algorithms/IterationNumberBasedAdaptiveTimeStepping.h b/NumLib/TimeStepping/Algorithms/IterationNumberBasedAdaptiveTimeStepping.h
index 16d38f414b40bd470227954e010698aa7f9e097d..fe2c3db2e7df6ba4de69073fad5e077817a9fe48 100644
--- a/NumLib/TimeStepping/Algorithms/IterationNumberBasedAdaptiveTimeStepping.h
+++ b/NumLib/TimeStepping/Algorithms/IterationNumberBasedAdaptiveTimeStepping.h
@@ -9,8 +9,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef ITERATIONNUMBERBASEDADAPTIVETIMESTEPPING_H_
-#define ITERATIONNUMBERBASEDADAPTIVETIMESTEPPING_H_
+#pragma once
 
 #include <vector>
 
@@ -142,5 +141,3 @@ private:
 };
 
 } // NumLib
-
-#endif // NEWTONADAPTIVETIMESTEPPING_H_
diff --git a/NumLib/TimeStepping/TimeStep.h b/NumLib/TimeStepping/TimeStep.h
index c7f53a94a14fdbcb770fd3b26e070423642f2dc7..07c66d869a4f59d72985e9c4eb36e4efb08a921a 100644
--- a/NumLib/TimeStepping/TimeStep.h
+++ b/NumLib/TimeStepping/TimeStep.h
@@ -9,8 +9,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef TIMESTEP_H_
-#define TIMESTEP_H_
+#pragma once
 
 #include <cstddef>
 
@@ -116,5 +115,3 @@ private:
 };
 
 } //NumLib
-
-#endif // TIMESTEP_H_
diff --git a/ProcessLib/AbstractJacobianAssembler.h b/ProcessLib/AbstractJacobianAssembler.h
index 412130f56790257bcce4ed89096ee769bf2963ca..7989d383b16673deb59c37180702ddc72422efd2 100644
--- a/ProcessLib/AbstractJacobianAssembler.h
+++ b/ProcessLib/AbstractJacobianAssembler.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_ABSTRACTJACOBIANASSEMBLER_H
-#define PROCESSLIB_ABSTRACTJACOBIANASSEMBLER_H
+#pragma once
 
 #include <vector>
 
@@ -34,5 +33,3 @@ public:
 };
 
 }  // ProcessLib
-
-#endif  // PROCESSLIB_ABSTRACTJACOBIANASSEMBLER_H
diff --git a/ProcessLib/AnalyticalJacobianAssembler.h b/ProcessLib/AnalyticalJacobianAssembler.h
index 1b04eb34e4122b6a3476ef4a859f2816dd7de555..5de7476d929b0c2a7cb89c3173ff935042822db8 100644
--- a/ProcessLib/AnalyticalJacobianAssembler.h
+++ b/ProcessLib/AnalyticalJacobianAssembler.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_ANALYTICALJACOBIANASSEMBLER_H
-#define PROCESSLIB_ANALYTICALJACOBIANASSEMBLER_H
+#pragma once
 
 #include "AbstractJacobianAssembler.h"
 
@@ -38,5 +37,3 @@ public:
 };
 
 }  // ProcessLib
-
-#endif  // PROCESSLIB_ANALYTICALJACOBIANASSEMBLER_H
diff --git a/ProcessLib/BoundaryCondition/BoundaryCondition.h b/ProcessLib/BoundaryCondition/BoundaryCondition.h
index ae2791336d45b0a9c8d1f5680377b28c46108b0a..ccf1b7ba364693eed93bf2077bef12447ae830c7 100644
--- a/ProcessLib/BoundaryCondition/BoundaryCondition.h
+++ b/ProcessLib/BoundaryCondition/BoundaryCondition.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_BOUNDARYCONDITION_H
-#define PROCESSLIB_BOUNDARYCONDITION_H
+#pragma once
 
 #include "NumLib/NumericsConfig.h"
 
@@ -119,5 +118,3 @@ protected:
 };
 
 }  // ProcessLib
-
-#endif  // PROCESSLIB_BOUNDARYCONDITION_H
diff --git a/ProcessLib/BoundaryCondition/BoundaryConditionCollection.h b/ProcessLib/BoundaryCondition/BoundaryConditionCollection.h
index b3419075a317401abd793b43309c9cf6bb6d86dd..e726ab7f5e0208dd367119593255525a9e6285b4 100644
--- a/ProcessLib/BoundaryCondition/BoundaryConditionCollection.h
+++ b/ProcessLib/BoundaryCondition/BoundaryConditionCollection.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_BOUNDARYCONDITIONCOLLECTION_H
-#define PROCESSLIB_BOUNDARYCONDITIONCOLLECTION_H
+#pragma once
 
 #include "NumLib/IndexValueVector.h"
 #include "ProcessLib/ProcessVariable.h"
@@ -54,5 +53,3 @@ private:
 
 
 }  // ProcessLib
-
-#endif  // PROCESSLIB_BOUNDARYCONDITIONCOLLECTION_H
diff --git a/ProcessLib/BoundaryCondition/BoundaryConditionConfig.h b/ProcessLib/BoundaryCondition/BoundaryConditionConfig.h
index 5621cb27c7fd9a58d0d25eb9c5e96ad15335b407..17bcb4aeae1d9ec35a0aae81f49bb20f2c761698 100644
--- a/ProcessLib/BoundaryCondition/BoundaryConditionConfig.h
+++ b/ProcessLib/BoundaryCondition/BoundaryConditionConfig.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_BOUNDARYCONDITIONCONFIG_H
-#define PROCESSLIB_BOUNDARYCONDITIONCONFIG_H
+#pragma once
 
 #include "BaseLib/ConfigTree.h"
 #include "GeoLib/GEOObjects.h"
@@ -40,5 +39,3 @@ struct BoundaryConditionConfig final
 };
 
 }  // ProcessLib
-
-#endif  // PROCESSLIB_BOUNDARYCONDITIONCONFIG_H
diff --git a/ProcessLib/BoundaryCondition/DirichletBoundaryCondition.h b/ProcessLib/BoundaryCondition/DirichletBoundaryCondition.h
index f38a2f1ecd8a25997aaec0b2a960c98f8a2109ec..ce485b3b7f0676138d1d540d064eeae260951a3b 100644
--- a/ProcessLib/BoundaryCondition/DirichletBoundaryCondition.h
+++ b/ProcessLib/BoundaryCondition/DirichletBoundaryCondition.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_DIRICHLETBOUNDARYCONDITION_H
-#define PROCESSLIB_DIRICHLETBOUNDARYCONDITION_H
+#pragma once
 
 #include "NumLib/DOF/LocalToGlobalIndexMap.h"
 #include "NumLib/IndexValueVector.h"
@@ -63,5 +62,3 @@ std::unique_ptr<DirichletBoundaryCondition> createDirichletBoundaryCondition(
     const std::vector<std::unique_ptr<ProcessLib::ParameterBase>>& parameters);
 
 }  // namespace ProcessLib
-
-#endif  // PROCESSLIB_DIRICHLETBOUNDARYCONDITION_H
diff --git a/ProcessLib/BoundaryCondition/GenericNaturalBoundaryCondition.h b/ProcessLib/BoundaryCondition/GenericNaturalBoundaryCondition.h
index 5f2aeea6917dbc0cd84cf7d704082431312304a6..46be6d1232ad1a114012f30cfdf112308532461f 100644
--- a/ProcessLib/BoundaryCondition/GenericNaturalBoundaryCondition.h
+++ b/ProcessLib/BoundaryCondition/GenericNaturalBoundaryCondition.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_GENERICNATURALBOUNDARYCONDITION_H
-#define PROCESSLIB_GENERICNATURALBOUNDARYCONDITION_H
+#pragma once
 
 #include "MeshLib/MeshSubset.h"
 #include "BoundaryCondition.h"
@@ -74,5 +73,3 @@ private:
 }  // ProcessLib
 
 #include "GenericNaturalBoundaryCondition-impl.h"
-
-#endif  // PROCESSLIB_GENERICNATURALBOUNDARYCONDITION_H
diff --git a/ProcessLib/BoundaryCondition/GenericNaturalBoundaryConditionLocalAssembler.h b/ProcessLib/BoundaryCondition/GenericNaturalBoundaryConditionLocalAssembler.h
index d995288c107ff53c7f49129b776056883b76f597..6ce3e4423e34ade4f0cd9680f311b35554c12a25 100644
--- a/ProcessLib/BoundaryCondition/GenericNaturalBoundaryConditionLocalAssembler.h
+++ b/ProcessLib/BoundaryCondition/GenericNaturalBoundaryConditionLocalAssembler.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_GENERICNATURALBOUNDARYCONDITIONLOCALASSEMBLER_H
-#define PROCESSLIB_GENERICNATURALBOUNDARYCONDITIONLOCALASSEMBLER_H
+#pragma once
 
 #include "NumLib/Fem/ShapeMatrixPolicy.h"
 #include "ProcessLib/Utils/InitShapeMatrices.h"
@@ -53,5 +52,3 @@ protected:
 };
 
 }  // ProcessLib
-
-#endif  // PROCESSLIB_GENERICNATURALBOUNDARYCONDITIONLOCALASSEMBLER_H
diff --git a/ProcessLib/BoundaryCondition/NeumannBoundaryCondition.h b/ProcessLib/BoundaryCondition/NeumannBoundaryCondition.h
index 7f00d04e4431c944ce19337ae43224404276c487..a0381cca18fa679d6ea04e5fd37335afcc7d430c 100644
--- a/ProcessLib/BoundaryCondition/NeumannBoundaryCondition.h
+++ b/ProcessLib/BoundaryCondition/NeumannBoundaryCondition.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_NEUMANNBOUNDARYCONDITION_H
-#define PROCESSLIB_NEUMANNBOUNDARYCONDITION_H
+#pragma once
 
 #include "ProcessLib/Parameter/Parameter.h"
 #include "GenericNaturalBoundaryCondition.h"
@@ -30,5 +29,3 @@ std::unique_ptr<NeumannBoundaryCondition> createNeumannBoundaryCondition(
     std::vector<std::unique_ptr<ParameterBase>> const& parameters);
 
 }  // ProcessLib
-
-#endif  // PROCESSLIB_NEUMANNBOUNDARYCONDITION_H
diff --git a/ProcessLib/BoundaryCondition/NeumannBoundaryConditionLocalAssembler.h b/ProcessLib/BoundaryCondition/NeumannBoundaryConditionLocalAssembler.h
index 1a58623c1c9ae68c3df487e67469b9861ef3e5dd..1a9b2c31b9a89050752d2c78ea734c5ade3bb86e 100644
--- a/ProcessLib/BoundaryCondition/NeumannBoundaryConditionLocalAssembler.h
+++ b/ProcessLib/BoundaryCondition/NeumannBoundaryConditionLocalAssembler.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_NEUMANNBOUNDARYCONDITIONLOCALASSEMBLER_H
-#define PROCESSLIB_NEUMANNBOUNDARYCONDITIONLOCALASSEMBLER_H
+#pragma once
 
 #include "NumLib/DOF/DOFTableUtil.h"
 #include "ProcessLib/Parameter/Parameter.h"
@@ -73,5 +72,3 @@ private:
 };
 
 }   // namespace ProcessLib
-
-#endif  // PROCESSLIB_NEUMANNBOUNDARYCONDITIONLOCALASSEMBLER_H
diff --git a/ProcessLib/BoundaryCondition/RobinBoundaryCondition.h b/ProcessLib/BoundaryCondition/RobinBoundaryCondition.h
index fa989c37894327bd2572f23b3b518c943c060af6..57cd2a415b150828b6cfd0e94ad865bcc09cda92 100644
--- a/ProcessLib/BoundaryCondition/RobinBoundaryCondition.h
+++ b/ProcessLib/BoundaryCondition/RobinBoundaryCondition.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_ROBINBOUNDARYCONDITION_H
-#define PROCESSLIB_ROBINBOUNDARYCONDITION_H
+#pragma once
 
 #include "GenericNaturalBoundaryCondition.h"
 #include "RobinBoundaryConditionLocalAssembler.h"
@@ -46,5 +45,3 @@ std::unique_ptr<RobinBoundaryCondition> createRobinBoundaryCondition(
     std::vector<std::unique_ptr<ParameterBase>> const& parameters);
 
 }  // ProcessLib
-
-#endif  // PROCESSLIB_ROBINBOUNDARYCONDITION_H
diff --git a/ProcessLib/BoundaryCondition/RobinBoundaryConditionLocalAssembler.h b/ProcessLib/BoundaryCondition/RobinBoundaryConditionLocalAssembler.h
index e947e9245edc928e6a7cd8c8da8c2fb92b321c7f..44a1ceddefc054c9df1242a589b76b8c26073c13 100644
--- a/ProcessLib/BoundaryCondition/RobinBoundaryConditionLocalAssembler.h
+++ b/ProcessLib/BoundaryCondition/RobinBoundaryConditionLocalAssembler.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_ROBINBOUNDARYCONDITIONLOCALASSEMBLER_H
-#define PROCESSLIB_ROBINBOUNDARYCONDITIONLOCALASSEMBLER_H
+#pragma once
 
 #include "NumLib/DOF/DOFTableUtil.h"
 #include "ProcessLib/Parameter/Parameter.h"
@@ -90,5 +89,3 @@ private:
 };
 
 }  // ProcessLib
-
-#endif  // PROCESSLIB_ROBINBOUNDARYCONDITIONLOCALASSEMBLER_H
diff --git a/ProcessLib/CachedSecondaryVariable.h b/ProcessLib/CachedSecondaryVariable.h
index 2129abb9f8caa06644a697c5b5387dd0a98f07ad..3a8d3e790cec924aec76312137bb2e8378d85616 100644
--- a/ProcessLib/CachedSecondaryVariable.h
+++ b/ProcessLib/CachedSecondaryVariable.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_CACHEDSECONDARYVARIABLE_H
-#define PROCESSLIB_CACHEDSECONDARYVARIABLE_H
+#pragma once
 
 #include "NumLib/Extrapolation/ExtrapolatableElementCollection.h"
 #include "NumLib/NamedFunctionProvider.h"
@@ -87,5 +86,3 @@ private:
 };
 
 }  // namespace ProcessLib
-
-#endif // PROCESSLIB_CACHEDSECONDARYVARIABLE_H
diff --git a/ProcessLib/CalculateSurfaceFlux/CalculateSurfaceFlux.h b/ProcessLib/CalculateSurfaceFlux/CalculateSurfaceFlux.h
index 1f6c75f448785149a990c5af5cae505ceaf8d76f..6bdbedb97def343f278d46d5c0f9d86bb8615ffd 100644
--- a/ProcessLib/CalculateSurfaceFlux/CalculateSurfaceFlux.h
+++ b/ProcessLib/CalculateSurfaceFlux/CalculateSurfaceFlux.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_CALCULATESURFACEFLUX_H_
-#define PROCESS_LIB_CALCULATESURFACEFLUX_H_
+#pragma once
 
 #include "ProcessLib/Process.h"
 #include "CalculateSurfaceFluxLocalAssembler.h"
@@ -43,5 +42,3 @@ private:
 };
 
 }   // namespace ProcessLib
-
-#endif  // PROCESS_LIB_CALCULATESURFACEFLUX_H_
diff --git a/ProcessLib/CalculateSurfaceFlux/CalculateSurfaceFluxLocalAssembler.h b/ProcessLib/CalculateSurfaceFlux/CalculateSurfaceFluxLocalAssembler.h
index 1764091d9b85bd37ea8ad3766fd6ba0b2805e289..b5d863c6e57ab176d43adf1876cffb98555a86b6 100644
--- a/ProcessLib/CalculateSurfaceFlux/CalculateSurfaceFluxLocalAssembler.h
+++ b/ProcessLib/CalculateSurfaceFlux/CalculateSurfaceFluxLocalAssembler.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_CALCULATESURFACEFLUXLOCALASSEMBLER_H
-#define PROCESSLIB_CALCULATESURFACEFLUXLOCALASSEMBLER_H
+#pragma once
 
 #include "NumLib/Fem/ShapeMatrixPolicy.h"
 
@@ -156,5 +155,3 @@ private:
 };
 
 }  // ProcessLib
-
-#endif  // PROCESSLIB_CALCULATESURFACEFLUXLOCALASSEMBLER_H
diff --git a/ProcessLib/CalculateSurfaceFlux/MapBulkElementPoint.h b/ProcessLib/CalculateSurfaceFlux/MapBulkElementPoint.h
index 8a0c345dca7f9f3332e7c4d1322f14a320b0894a..2ecea0628a20da03305030871821c46d91e39bba 100644
--- a/ProcessLib/CalculateSurfaceFlux/MapBulkElementPoint.h
+++ b/ProcessLib/CalculateSurfaceFlux/MapBulkElementPoint.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_CALCULATESURFACEFLUX_MAPBULKELEMENT_H
-#define PROCESSLIB_CALCULATESURFACEFLUX_MAPBULKELEMENT_H
+#pragma once
 
 #include <array>
 
@@ -67,4 +66,3 @@ MathLib::Point3d getBulkElementPoint(MeshLib::Mesh const& mesh,
                                      std::size_t bulk_face_id,
                                      MathLib::WeightedPoint3D const& wp);
 }  // end namespace ProcessLib
-#endif
diff --git a/ProcessLib/CentralDifferencesJacobianAssembler.h b/ProcessLib/CentralDifferencesJacobianAssembler.h
index 45d9dabaf4054f47536a4715a8cdf0af2964dc00..501d2a1a395827ee198d68255c293b12542eb061 100644
--- a/ProcessLib/CentralDifferencesJacobianAssembler.h
+++ b/ProcessLib/CentralDifferencesJacobianAssembler.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_CENTRALDIFFERENCESJACOBIANASSEMBLER_H
-#define PROCESSLIB_CENTRALDIFFERENCESJACOBIANASSEMBLER_H
+#pragma once
 
 #include <memory>
 #include "AbstractJacobianAssembler.h"
@@ -72,5 +71,3 @@ std::unique_ptr<CentralDifferencesJacobianAssembler>
 createCentralDifferencesJacobianAssembler(BaseLib::ConfigTree const& config);
 
 }  // ProcessLib
-
-#endif  // PROCESSLIB_CENTRALDIFFERENCESJACOBIANASSEMBLER_H
diff --git a/ProcessLib/CreateJacobianAssembler.h b/ProcessLib/CreateJacobianAssembler.h
index 6927cb1e20949495baddf54b890757aa7b750744..bf563ee3134b20590c9dabebfcb4a4f09608be71 100644
--- a/ProcessLib/CreateJacobianAssembler.h
+++ b/ProcessLib/CreateJacobianAssembler.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_CREATEJACOBIANASSEMBLER_H
-#define PROCESSLIB_CREATEJACOBIANASSEMBLER_H
+#pragma once
 
 #include "BaseLib/ConfigTree.h"
 
@@ -19,5 +18,3 @@ class AbstractJacobianAssembler;
 std::unique_ptr<AbstractJacobianAssembler> createJacobianAssembler(
     boost::optional<BaseLib::ConfigTree> const& config);
 }  // ProcessLib
-
-#endif  // PROCESSLIB_CREATEJACOBIANASSEMBLER_H
diff --git a/ProcessLib/Deformation/BMatrixPolicy.h b/ProcessLib/Deformation/BMatrixPolicy.h
index 1b9bcb8e2eb553acaee71773eed53d23c8d84314..9b673877e87c99847c549a128c612ce7e6eb549e 100644
--- a/ProcessLib/Deformation/BMatrixPolicy.h
+++ b/ProcessLib/Deformation/BMatrixPolicy.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_FEM_BMATRIXPOLICY_H_
-#define PROCESSLIB_FEM_BMATRIXPOLICY_H_
+#pragma once
 
 #include "NumLib/Fem/ShapeMatrixPolicy.h"
 
@@ -94,5 +93,3 @@ public:
     using BMatrixType = MatrixType<_kelvin_vector_size, _number_of_dof>;
 };
 }  // namespace ProcessLib
-
-#endif  // PROCESSLIB_FEM_BMATRIXPOLICY_H_
diff --git a/ProcessLib/Deformation/LinearBMatrix.h b/ProcessLib/Deformation/LinearBMatrix.h
index 9ba34f693da606d619ae5584cf8f89682e1b998c..1d122c9a14244f4df6cb8fb60f9eeb419907c1ed 100644
--- a/ProcessLib/Deformation/LinearBMatrix.h
+++ b/ProcessLib/Deformation/LinearBMatrix.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_FEM_DEFORMATION_LINEARBMATRIX_H_
-#define PROCESSLIB_FEM_DEFORMATION_LINEARBMATRIX_H_
+#pragma once
 
 #include <cmath>
 
@@ -78,5 +77,3 @@ void computeBMatrix(DNDX_Type const& dNdx,
 
 }  // namespace LinearBMatrix
 }  // namespace ProcessLib
-
-#endif  // PROCESSLIB_FEM_DEFORMATION_LINEARBMATRIX_H_
diff --git a/ProcessLib/ExtrapolatorData.h b/ProcessLib/ExtrapolatorData.h
index 586a6e99468014bdc35fa5041a2cb08068c0c8b4..a0e90dec9b8e14743d1b3a6ecc36dadcc7800bd4 100644
--- a/ProcessLib/ExtrapolatorData.h
+++ b/ProcessLib/ExtrapolatorData.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_EXTRAPOLATORDATA_H
-#define PROCESSLIB_EXTRAPOLATORDATA_H
+#pragma once
 
 #include <memory>
 #include "NumLib/DOF/LocalToGlobalIndexMap.h"
@@ -97,6 +96,3 @@ private:
 };
 
 } // namespace ProcessLib
-
-
-#endif // PROCESSLIB_EXTRAPOLATORDATA_H
diff --git a/ProcessLib/GlobalVectorFromNamedFunction.h b/ProcessLib/GlobalVectorFromNamedFunction.h
index 42a90e6a5678b0326983eb5bd1fbefcbbe22c4bc..83ab3aa8e478d3d3e457c4e5c2298c8ffa899628 100644
--- a/ProcessLib/GlobalVectorFromNamedFunction.h
+++ b/ProcessLib/GlobalVectorFromNamedFunction.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_GLOBALVECTORFROMNAMEDFUNCTION_H
-#define PROCESSLIB_GLOBALVECTORFROMNAMEDFUNCTION_H
+#pragma once
 
 #include "MeshLib/Mesh.h"
 #include "NumLib/DOF/LocalToGlobalIndexMap.h"
@@ -54,5 +53,3 @@ private:
     SecondaryVariableContext& _context;
 };
 }  // namespace ProcessLib
-
-#endif  // PROCESSLIB_GLOBALVECTORFROMNAMEDFUNCTION_H
diff --git a/ProcessLib/GroundwaterFlow/CreateGroundwaterFlowProcess.h b/ProcessLib/GroundwaterFlow/CreateGroundwaterFlowProcess.h
index 2e8b844d0a02704d144e18a59c712baf65541c90..200124fb4ebd998f59b1f4f784229b603abd2510 100644
--- a/ProcessLib/GroundwaterFlow/CreateGroundwaterFlowProcess.h
+++ b/ProcessLib/GroundwaterFlow/CreateGroundwaterFlowProcess.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_CREATE_GROUNDWATERFLOWPROCESS_H_
-#define PROCESS_LIB_CREATE_GROUNDWATERFLOWPROCESS_H_
+#pragma once
 
 #include <memory>
 #include "ProcessLib/Process.h"
@@ -30,5 +29,3 @@ std::unique_ptr<Process> createGroundwaterFlowProcess(
 
 }   // namespace GroundwaterFlow
 }   // namespace ProcessLib
-
-#endif  // PROCESS_LIB_CREATE_GROUNDWATERFLOWPROCESS_H_
diff --git a/ProcessLib/GroundwaterFlow/GroundwaterFlowFEM.h b/ProcessLib/GroundwaterFlow/GroundwaterFlowFEM.h
index b3ed598fd73c1983cc32b9cb839a9a2d1bc34a1c..029b46ba4884f53f8c2c3fa7f842f93b5ff54d31 100644
--- a/ProcessLib/GroundwaterFlow/GroundwaterFlowFEM.h
+++ b/ProcessLib/GroundwaterFlow/GroundwaterFlowFEM.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_GROUNDWATERFLOW_FEM_H_
-#define PROCESS_LIB_GROUNDWATERFLOW_FEM_H_
+#pragma once
 
 #include <vector>
 
@@ -221,5 +220,3 @@ private:
 
 }  // namespace GroundwaterFlow
 }  // namespace ProcessLib
-
-#endif  // PROCESS_LIB_GROUNDWATERFLOW_FEM_H_
diff --git a/ProcessLib/GroundwaterFlow/GroundwaterFlowProcess.h b/ProcessLib/GroundwaterFlow/GroundwaterFlowProcess.h
index b6603b88ac485a3fc0c0ded0f609fe4f4b04af79..f609740a86325e7ffc94238639559df3cbce148c 100644
--- a/ProcessLib/GroundwaterFlow/GroundwaterFlowProcess.h
+++ b/ProcessLib/GroundwaterFlow/GroundwaterFlowProcess.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_GROUNDWATERFLOWPROCESS_H_
-#define PROCESS_LIB_GROUNDWATERFLOWPROCESS_H_
+#pragma once
 
 #include "NumLib/DOF/LocalToGlobalIndexMap.h"
 #include "ProcessLib/Process.h"
@@ -118,5 +117,3 @@ private:
 
 }   // namespace GroundwaterFlow
 }   // namespace ProcessLib
-
-#endif  // PROCESS_LIB_GROUNDWATERFLOWPROCESS_H_
diff --git a/ProcessLib/GroundwaterFlow/GroundwaterFlowProcessData.h b/ProcessLib/GroundwaterFlow/GroundwaterFlowProcessData.h
index 28e668c8b0af1ad5c04766e62bb9890f29621c3a..9218c2f59879cd68b95df2c3d70538d8dd1c1baa 100644
--- a/ProcessLib/GroundwaterFlow/GroundwaterFlowProcessData.h
+++ b/ProcessLib/GroundwaterFlow/GroundwaterFlowProcessData.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_GROUNDWATERFLOW_GROUNDWATERFLOWPROCESSDATA_H
-#define PROCESSLIB_GROUNDWATERFLOW_GROUNDWATERFLOWPROCESSDATA_H
+#pragma once
 
 namespace MeshLib
 {
@@ -50,5 +49,3 @@ struct GroundwaterFlowProcessData
 
 } // namespace GroundwaterFlow
 } // namespace ProcessLib
-
-#endif // PROCESSLIB_GROUNDWATERFLOW_GROUNDWATERFLOWPROCESSDATA_H
diff --git a/ProcessLib/HT/CreateHTProcess.h b/ProcessLib/HT/CreateHTProcess.h
index d7b8f6ec094e8dd47f15ee3ed6b8d3c7fc88eff3..fb71e3df28290280954f762c9dd8e1c4489e74c8 100644
--- a/ProcessLib/HT/CreateHTProcess.h
+++ b/ProcessLib/HT/CreateHTProcess.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_CREATE_HTPROCESS_H_
-#define PROCESS_LIB_CREATE_HTPROCESS_H_
+#pragma once
 
 #include <memory>
 #include "ProcessLib/Process.h"
@@ -27,5 +26,3 @@ std::unique_ptr<Process> createHTProcess(
 
 }  // namespace HT
 }  // namespace ProcessLib
-
-#endif  // PROCESS_LIB_CREATE_HTPROCESS_H_
diff --git a/ProcessLib/HT/HTFEM.h b/ProcessLib/HT/HTFEM.h
index a0598e1b3efb322d35f52fdd39623fe7e7460952..297873c7c76d8b10ebaf26fd89389b5dde3b9f64 100644
--- a/ProcessLib/HT/HTFEM.h
+++ b/ProcessLib/HT/HTFEM.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_HTPROCESS_FEM_H_
-#define PROCESS_LIB_HTPROCESS_FEM_H_
+#pragma once
 
 #include <iostream>
 #include <Eigen/Dense>
@@ -261,5 +260,3 @@ private:
 
 }  // namespace HT
 }  // namespace ProcessLib
-
-#endif  // PROCESS_LIB_HT_FEM_H_
diff --git a/ProcessLib/HT/HTProcess.h b/ProcessLib/HT/HTProcess.h
index 5e73ad3f3bc80b73fee40de11e29ca36a9a3ede0..355dba18b5b6247ed94fac2eb8ba09fd0450502b 100644
--- a/ProcessLib/HT/HTProcess.h
+++ b/ProcessLib/HT/HTProcess.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_HTPROCESS_H_
-#define PROCESS_LIB_HTPROCESS_H_
+#pragma once
 
 #include "HTFEM.h"
 #include "HTProcessData.h"
@@ -80,5 +79,3 @@ private:
 
 }  // namespace HT
 }  // namespace ProcessLib
-
-#endif // PROCESS_LIB_HTPROCESS_H_
diff --git a/ProcessLib/HT/HTProcessData.h b/ProcessLib/HT/HTProcessData.h
index 1b5968e12aef4bfd8b60d555c15df22b266986d3..b32e65184c2d9bfc789ea428c13b832e9cb27fea 100644
--- a/ProcessLib/HT/HTProcessData.h
+++ b/ProcessLib/HT/HTProcessData.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_HT_HTPROCESSDATA_H
-#define PROCESSLIB_HT_HTPROCESSDATA_H
+#pragma once
 
 namespace MeshLib
 {
@@ -112,5 +111,3 @@ struct HTProcessData
 
 }  // namespace HT
 }  // namespace ProcessLib
-
-#endif // PROCESSLIB_HT_HTPROCESSDATA_H
diff --git a/ProcessLib/HeatConduction/CreateHeatConductionProcess.h b/ProcessLib/HeatConduction/CreateHeatConductionProcess.h
index 9ce980f2e9aae1d182c784f8eecbff528fd715d8..cb529e930dc72fd7971cf54bab644cf116b39747 100644
--- a/ProcessLib/HeatConduction/CreateHeatConductionProcess.h
+++ b/ProcessLib/HeatConduction/CreateHeatConductionProcess.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_CREATE_HEATCONDUCTIONPROCESS_H_
-#define PROCESS_LIB_CREATE_HEATCONDUCTIONPROCESS_H_
+#pragma once
 
 #include <memory>
 #include "ProcessLib/Process.h"
@@ -27,5 +26,3 @@ std::unique_ptr<Process> createHeatConductionProcess(
 
 }  // namespace HeatConduction
 }  // namespace ProcessLib
-
-#endif  // PROCESS_LIB_CREATE_HEATCONDUCTIONPROCESS_H_
diff --git a/ProcessLib/HeatConduction/HeatConductionFEM.h b/ProcessLib/HeatConduction/HeatConductionFEM.h
index fb33be2eb61b0eb6e0f8835a8ebbfa83691dc87f..1380762dd27fc277dc69a2926549df6c38ae39b5 100644
--- a/ProcessLib/HeatConduction/HeatConductionFEM.h
+++ b/ProcessLib/HeatConduction/HeatConductionFEM.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_HEATCONDUCTION_FEM_H_
-#define PROCESS_LIB_HEATCONDUCTION_FEM_H_
+#pragma once
 
 #include <vector>
 
@@ -193,5 +192,3 @@ private:
 
 }  // namespace HeatConduction
 }  // namespace ProcessLib
-
-#endif  // PROCESS_LIB_HEATCONDUCTION_FEM_H_
diff --git a/ProcessLib/HeatConduction/HeatConductionProcess.h b/ProcessLib/HeatConduction/HeatConductionProcess.h
index dc5046aa6f5ea03c4618d51b69601c7be2ddaeb7..dd2c340e1b09560379d108e417a95a7cb1399426 100644
--- a/ProcessLib/HeatConduction/HeatConductionProcess.h
+++ b/ProcessLib/HeatConduction/HeatConductionProcess.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_HEATCONDUCTIONPROCESS_H_
-#define PROCESS_LIB_HEATCONDUCTIONPROCESS_H_
+#pragma once
 
 #include "ProcessLib/Process.h"
 #include "HeatConductionFEM.h"
@@ -65,5 +64,3 @@ private:
 
 }  // namespace HeatConduction
 }  // namespace ProcessLib
-
-#endif  // PROCESS_LIB_HEATCONDUCTIONPROCESS_H_
diff --git a/ProcessLib/HeatConduction/HeatConductionProcessData.h b/ProcessLib/HeatConduction/HeatConductionProcessData.h
index 124401a555e79bacb297797a11ab1f9749e42b36..06d72977862feb8791f44aabe25ea686841bd765 100644
--- a/ProcessLib/HeatConduction/HeatConductionProcessData.h
+++ b/ProcessLib/HeatConduction/HeatConductionProcessData.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_HEATCONDUCTION_HEATCONDUCTIONPROCESSDATA_H
-#define PROCESSLIB_HEATCONDUCTION_HEATCONDUCTIONPROCESSDATA_H
+#pragma once
 
 namespace MeshLib
 {
@@ -57,5 +56,3 @@ struct HeatConductionProcessData
 
 }  // namespace HeatConduction
 }  // namespace ProcessLib
-
-#endif  // PROCESSLIB_HEATCONDUCTION_HEATCONDUCTIONPROCESSDATA_H
diff --git a/ProcessLib/HydroMechanics/CreateHydroMechanicsProcess.h b/ProcessLib/HydroMechanics/CreateHydroMechanicsProcess.h
index 4f5c7136bb0239baeac569179e48bffd6d3127d9..bf68fcf22751d85ab289c98cf85032a961398719 100644
--- a/ProcessLib/HydroMechanics/CreateHydroMechanicsProcess.h
+++ b/ProcessLib/HydroMechanics/CreateHydroMechanicsProcess.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_CREATEHYDROMECHANICSPROCESS_H_
-#define PROCESS_LIB_CREATEHYDROMECHANICSPROCESS_H_
+#pragma once
 
 #include "ProcessLib/Process.h"
 
@@ -27,5 +26,3 @@ std::unique_ptr<Process> createHydroMechanicsProcess(
 
 }  // namespace HydroMechanics
 }  // namespace ProcessLib
-
-#endif  // PROCESS_LIB_CREATEHYDROMECHANICSPROCESS_H_
diff --git a/ProcessLib/HydroMechanics/CreateLocalAssemblers.h b/ProcessLib/HydroMechanics/CreateLocalAssemblers.h
index 4e34e7584d8ddbc1aa48ac5c68daee7eb6a69ebd..305e574426937de343d87067dae3393120309eeb 100644
--- a/ProcessLib/HydroMechanics/CreateLocalAssemblers.h
+++ b/ProcessLib/HydroMechanics/CreateLocalAssemblers.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef PROCESSLIB_HYDROMECHANICS_CREATE_LOCAL_ASSEMBLERS_H_
-#define PROCESSLIB_HYDROMECHANICS_CREATE_LOCAL_ASSEMBLERS_H_
+#pragma once
 
 #include <vector>
 
@@ -101,5 +100,3 @@ void createLocalAssemblers(
 }  // HydroMechanics
 
 }  // ProcessLib
-
-#endif  // PROCESSLIB_HYDROMECHANICS_CREATE_LOCAL_ASSEMBLERS_H_
diff --git a/ProcessLib/HydroMechanics/HydroMechanicsFEM.h b/ProcessLib/HydroMechanics/HydroMechanicsFEM.h
index e4a63ceceac9e3be5e3091704e9cf006798df1ca..c39a47baf5d6548b0e6ddbc1c5a18ade4f83c67c 100644
--- a/ProcessLib/HydroMechanics/HydroMechanicsFEM.h
+++ b/ProcessLib/HydroMechanics/HydroMechanicsFEM.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_HYDROMECHANICS_FEM_H_
-#define PROCESS_LIB_HYDROMECHANICS_FEM_H_
+#pragma once
 
 #include <iostream>
 #include <memory>
@@ -402,5 +401,3 @@ public:
 
 }  // namespace HydroMechanics
 }  // namespace ProcessLib
-
-#endif  // PROCESS_LIB_HYDROMECHANICS_FEM_H_
diff --git a/ProcessLib/HydroMechanics/HydroMechanicsProcess-fwd.h b/ProcessLib/HydroMechanics/HydroMechanicsProcess-fwd.h
index de0adc0afa08d76a3a93d70b15ace1c517992e3d..c0a54772a7badf7cc291a6add13639a64d44bc1d 100644
--- a/ProcessLib/HydroMechanics/HydroMechanicsProcess-fwd.h
+++ b/ProcessLib/HydroMechanics/HydroMechanicsProcess-fwd.h
@@ -7,12 +7,9 @@
  *
  */
 
-#ifndef PROCESS_LIB_HYDROMECHANICSPROCESS_FWD_H_
-#define PROCESS_LIB_HYDROMECHANICSPROCESS_FWD_H_
+#pragma once
 
 #include "HydroMechanicsProcess.h"
 
 extern template class ProcessLib::HydroMechanics::HydroMechanicsProcess<2>;
 extern template class ProcessLib::HydroMechanics::HydroMechanicsProcess<3>;
-
-#endif  // PROCESS_LIB_HYDROMECHANICSPROCESS_FWD_H_
diff --git a/ProcessLib/HydroMechanics/HydroMechanicsProcess.h b/ProcessLib/HydroMechanics/HydroMechanicsProcess.h
index d219b8c1009625109f264ae0e90a177a086e23bf..3087dfb382a677c1f10d654376fb1bf5166b3b04 100644
--- a/ProcessLib/HydroMechanics/HydroMechanicsProcess.h
+++ b/ProcessLib/HydroMechanics/HydroMechanicsProcess.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_HYDROMECHANICSPROCESS_H_
-#define PROCESS_LIB_HYDROMECHANICSPROCESS_H_
+#pragma once
 
 #include <cassert>
 
@@ -163,5 +162,3 @@ private:
 
 }  // namespace HydroMechanics
 }  // namespace ProcessLib
-
-#endif  // PROCESS_LIB_HYDROMECHANICSPROCESS_H_
diff --git a/ProcessLib/HydroMechanics/HydroMechanicsProcessData.h b/ProcessLib/HydroMechanics/HydroMechanicsProcessData.h
index 7e2b6dba3da5f9ba838502d483c1ac1e04864148..1172958b3afe7646f9d651306039310834cc9f30 100644
--- a/ProcessLib/HydroMechanics/HydroMechanicsProcessData.h
+++ b/ProcessLib/HydroMechanics/HydroMechanicsProcessData.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_HYDROMECHANICS_HYDROMECHANICSPROCESSDATA_H_
-#define PROCESSLIB_HYDROMECHANICS_HYDROMECHANICSPROCESSDATA_H_
+#pragma once
 
 #include <Eigen/Dense>
 
@@ -100,5 +99,3 @@ struct HydroMechanicsProcessData
 
 }  // namespace HydroMechanics
 }  // namespace ProcessLib
-
-#endif  // PROCESSLIB_HYDROMECHANICS_HYDROMECHANICSPROCESSDATA_H_
diff --git a/ProcessLib/HydroMechanics/LocalDataInitializer.h b/ProcessLib/HydroMechanics/LocalDataInitializer.h
index afaf2db2afb597881f069f60fa3bc958b96f8409..2869c4cd017b5ddeaf264ee926d8fa0662f80781 100644
--- a/ProcessLib/HydroMechanics/LocalDataInitializer.h
+++ b/ProcessLib/HydroMechanics/LocalDataInitializer.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_HYDROMECHANICS_LOCALDATAINITIALIZER_H_
-#define PROCESSLIB_HYDROMECHANICS_LOCALDATAINITIALIZER_H_
+#pragma once
 
 #include <functional>
 #include <memory>
@@ -289,5 +288,3 @@ private:
 #undef ENABLED_ELEMENT_TYPE_TRI
 #undef ENABLED_ELEMENT_TYPE_QUAD
 #undef OGS_ENABLED_ELEMENTS
-
-#endif  // PROCESSLIB_HYDROMECHANICS_LOCALDATAINITIALIZER_H_
diff --git a/ProcessLib/LIE/BoundaryCondition/BoundaryConditionBuilder.h b/ProcessLib/LIE/BoundaryCondition/BoundaryConditionBuilder.h
index 8fb3cebe87cbd51e888c746c91083e7922913383..d4276b253f17a57bcdfe914c09ebc1edcd99847b 100644
--- a/ProcessLib/LIE/BoundaryCondition/BoundaryConditionBuilder.h
+++ b/ProcessLib/LIE/BoundaryCondition/BoundaryConditionBuilder.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_BOUNDARYCONDITIONBUILDER_H_
-#define PROCESSLIB_LIE_BOUNDARYCONDITIONBUILDER_H_
+#pragma once
 
 #include "NumLib/NumericsConfig.h"
 
@@ -56,5 +55,3 @@ private:
 
 }  // LIE
 }  // ProcessLib
-
-#endif // PROCESSLIB_LIE_BOUNDARYCONDITIONBUILDER_H_
diff --git a/ProcessLib/LIE/BoundaryCondition/GenericNaturalBoundaryCondition-impl.h b/ProcessLib/LIE/BoundaryCondition/GenericNaturalBoundaryCondition-impl.h
index c2f2e4044cf74b327c6200ee03eed71812579c68..7fe1d52b7c749971d9530ae945a05608adb3d84d 100644
--- a/ProcessLib/LIE/BoundaryCondition/GenericNaturalBoundaryCondition-impl.h
+++ b/ProcessLib/LIE/BoundaryCondition/GenericNaturalBoundaryCondition-impl.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_GENERICNATURALBOUNDARYCONDITION_IMPL_H_
-#define PROCESSLIB_LIE_GENERICNATURALBOUNDARYCONDITION_IMPL_H_
+#pragma once
 
 #include "GenericNaturalBoundaryCondition.h"
 
@@ -98,5 +97,3 @@ void GenericNaturalBoundaryCondition<
 
 }  // LIE
 }  // ProcessLib
-
-#endif // PROCESSLIB_LIE_GENERICNATURALBOUNDARYCONDITION_IMPL_H_
diff --git a/ProcessLib/LIE/BoundaryCondition/GenericNaturalBoundaryCondition.h b/ProcessLib/LIE/BoundaryCondition/GenericNaturalBoundaryCondition.h
index 5a808a5704099256ee755c96618511b0f5847d37..2f856a85a7ed2cccf62ae6fc3fff60d6280e0607 100644
--- a/ProcessLib/LIE/BoundaryCondition/GenericNaturalBoundaryCondition.h
+++ b/ProcessLib/LIE/BoundaryCondition/GenericNaturalBoundaryCondition.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_GENERICNATURALBOUNDARYCONDITION_H_
-#define PROCESSLIB_LIE_GENERICNATURALBOUNDARYCONDITION_H_
+#pragma once
 
 #include "MeshLib/MeshSubset.h"
 #include "ProcessLib/BoundaryCondition/BoundaryCondition.h"
@@ -80,5 +79,3 @@ private:
 }  // ProcessLib
 
 #include "GenericNaturalBoundaryCondition-impl.h"
-
-#endif // PROCESSLIB_LIE_GENERICNATURALBOUNDARYCONDITION_H_
diff --git a/ProcessLib/LIE/BoundaryCondition/NeumannBoundaryCondition.h b/ProcessLib/LIE/BoundaryCondition/NeumannBoundaryCondition.h
index 3bf1e8c0efefc0769d062b4eab743f70334a322f..c3fddf08c0d5e1ac2fa1b5203a1f0c858312f29a 100644
--- a/ProcessLib/LIE/BoundaryCondition/NeumannBoundaryCondition.h
+++ b/ProcessLib/LIE/BoundaryCondition/NeumannBoundaryCondition.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_NEUMANNBOUNDARYCONDITION_H_
-#define PROCESSLIB_LIE_NEUMANNBOUNDARYCONDITION_H_
+#pragma once
 
 #include "ProcessLib/Parameter/Parameter.h"
 #include "ProcessLib/BoundaryCondition/BoundaryCondition.h"
@@ -40,5 +39,3 @@ createNeumannBoundaryCondition(
 
 }  // LIE
 }  // ProcessLib
-
-#endif // PROCESSLIB_LIE_NEUMANNBOUNDARYCONDITION_H_
diff --git a/ProcessLib/LIE/BoundaryCondition/NeumannBoundaryConditionLocalAssembler.h b/ProcessLib/LIE/BoundaryCondition/NeumannBoundaryConditionLocalAssembler.h
index 948bbe22f0ba25e30d62efb7557ac0b884052a91..3eff9000f028218d26faf01112474aa7de1df748 100644
--- a/ProcessLib/LIE/BoundaryCondition/NeumannBoundaryConditionLocalAssembler.h
+++ b/ProcessLib/LIE/BoundaryCondition/NeumannBoundaryConditionLocalAssembler.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_NEUMANNBOUNDARYCONDITION_LOCALASSEMBLER_H_
-#define PROCESSLIB_LIE_NEUMANNBOUNDARYCONDITION_LOCALASSEMBLER_H_
+#pragma once
 
 #include "NumLib/DOF/DOFTableUtil.h"
 
@@ -94,5 +93,3 @@ private:
 
 }   // namespace LIE
 }   // namespace ProcessLib
-
-#endif // PROCESSLIB_LIE_NEUMANNBOUNDARYCONDITION_LOCALASSEMBLER_H_
diff --git a/ProcessLib/LIE/Common/FractureProperty.h b/ProcessLib/LIE/Common/FractureProperty.h
index 25414f6514f1604287893c8a4eda8259432c25ca..663432327840edcd9303d711c8bd0878c83ac99a 100644
--- a/ProcessLib/LIE/Common/FractureProperty.h
+++ b/ProcessLib/LIE/Common/FractureProperty.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_COMMON_FRACTUREPROPERTY_H_
-#define PROCESSLIB_LIE_COMMON_FRACTUREPROPERTY_H_
+#pragma once
 
 #include <Eigen/Eigen>
 
@@ -55,5 +54,3 @@ inline void setFractureProperty(unsigned dim, MeshLib::Element const& e,
 
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif // PROCESSLIB_LIE_COMMON_FRACTUREPROPERTY_H_
diff --git a/ProcessLib/LIE/Common/HMatrixUtils.h b/ProcessLib/LIE/Common/HMatrixUtils.h
index c7780ee72e22697e7fd786694103ac9b6c861a2e..6a80b9600d113d6d865e71099c2125245ee81a0c 100644
--- a/ProcessLib/LIE/Common/HMatrixUtils.h
+++ b/ProcessLib/LIE/Common/HMatrixUtils.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_COMMON_HMATRIXPOLICYTYPE_H_
-#define PROCESSLIB_LIE_COMMON_HMATRIXPOLICYTYPE_H_
+#pragma once
 
 #include "NumLib/Fem/ShapeMatrixPolicy.h"
 
@@ -62,5 +61,3 @@ void computeHMatrix(N_Type const& N, HMatrixType& H)
 }
 
 }  // namespace ProcessLib
-
-#endif // PROCESSLIB_LIE_COMMON_HMATRIXPOLICYTYPE_H_
diff --git a/ProcessLib/LIE/Common/LevelSetFunction.h b/ProcessLib/LIE/Common/LevelSetFunction.h
index e663268cea2e42fa52d9370df6197defa089ae73..e373103a22c5fe67997068b77ea6c2bbecf819f6 100644
--- a/ProcessLib/LIE/Common/LevelSetFunction.h
+++ b/ProcessLib/LIE/Common/LevelSetFunction.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef PROCESSLIB_LIE_COMMON_LEVELSETFUNCTION_H_
-#define PROCESSLIB_LIE_COMMON_LEVELSETFUNCTION_H_
+#pragma once
 
 namespace ProcessLib
 {
@@ -25,5 +24,3 @@ double calculateLevelSetFunction(
 
 } // LIE
 } // ProcessLib
-
-#endif // PROCESSLIB_LIE_COMMON_LEVELSETFUNCTION_H_
diff --git a/ProcessLib/LIE/Common/MeshUtils.h b/ProcessLib/LIE/Common/MeshUtils.h
index ab4588f5f6ab8d9112d1741d1e49b03f3c9974ad..a3235bd48538f39b78e49898d8240cbe4603244f 100644
--- a/ProcessLib/LIE/Common/MeshUtils.h
+++ b/ProcessLib/LIE/Common/MeshUtils.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef PROCESSLIB_LIE_COMMON_MESHUTILS_H_
-#define PROCESSLIB_LIE_COMMON_MESHUTILS_H_
+#pragma once
 
 #include <vector>
 
@@ -43,5 +42,3 @@ void getFractureMatrixDataInMesh(
 
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif // PROCESSLIB_LIE_COMMON_MESHUTILS_H_
diff --git a/ProcessLib/LIE/Common/PostUtils.h b/ProcessLib/LIE/Common/PostUtils.h
index 1f57aba72cd912ca22542b319bf044e9ee8dfba7..2492cd0efe11886046dc354ec92c5450fe18c5e2 100644
--- a/ProcessLib/LIE/Common/PostUtils.h
+++ b/ProcessLib/LIE/Common/PostUtils.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef PROCESSLIB_LIE_COMMON_POSTUTILS_H_
-#define PROCESSLIB_LIE_COMMON_POSTUTILS_H_
+#pragma once
 
 #include <map>
 #include <memory>
@@ -48,5 +47,3 @@ private:
 
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif // PROCESSLIB_LIE_COMMON_POSTUTILS_H_
diff --git a/ProcessLib/LIE/Common/Utils.h b/ProcessLib/LIE/Common/Utils.h
index f8e9a98f92d2f02720fa80ca297ed1c7c1da40f6..8b23708cc16be46cc438f5086d9efda8fc6e7de6 100644
--- a/ProcessLib/LIE/Common/Utils.h
+++ b/ProcessLib/LIE/Common/Utils.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef PROCESSLIB_LIE_COMMON_UTILS_H_
-#define PROCESSLIB_LIE_COMMON_UTILS_H_
+#pragma once
 
 #include <Eigen/Eigen>
 
@@ -41,5 +40,3 @@ MathLib::Point3d computePhysicalCoordinates(MeshLib::Element const&e, Eigen::Mat
 
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif
diff --git a/ProcessLib/LIE/HydroMechanics/CreateHydroMechanicsProcess.h b/ProcessLib/LIE/HydroMechanics/CreateHydroMechanicsProcess.h
index 74c9b98a2217a73f6d2fb96db7c659dbb68284f7..28657054ee0ec8002aff15c21595ed0ceb0e46d4 100644
--- a/ProcessLib/LIE/HydroMechanics/CreateHydroMechanicsProcess.h
+++ b/ProcessLib/LIE/HydroMechanics/CreateHydroMechanicsProcess.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_LIE_CREATEHYDROMECHANICSPROCESS_H_
-#define PROCESS_LIB_LIE_CREATEHYDROMECHANICSPROCESS_H_
+#pragma once
 
 #include <memory>
 #include <vector>
@@ -33,5 +32,3 @@ std::unique_ptr<Process> createHydroMechanicsProcess(
 }  // namespace HydroMechanics
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif  // PROCESS_LIB_LIE_CREATEHYDROMECHANICSPROCESS_H_
diff --git a/ProcessLib/LIE/HydroMechanics/HydroMechanicsProcess-fwd.h b/ProcessLib/LIE/HydroMechanics/HydroMechanicsProcess-fwd.h
index adb84609b3980faf3dcaf1abba0fc292d18c8086..340890b30afc84ad7d921e141e4a5eb3c046eb83 100644
--- a/ProcessLib/LIE/HydroMechanics/HydroMechanicsProcess-fwd.h
+++ b/ProcessLib/LIE/HydroMechanics/HydroMechanicsProcess-fwd.h
@@ -7,11 +7,8 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_HYDROMECHANICSPROCESS_FWD_H_
-#define PROCESSLIB_LIE_HYDROMECHANICSPROCESS_FWD_H_
+#pragma once
 
 #include "HydroMechanicsProcess.h"
 
 extern template class ProcessLib::LIE::HydroMechanics::HydroMechanicsProcess<2>;
-
-#endif  // PROCESSLIB_LIE_HYDROMECHANICSPROCESS_FWD_H_
diff --git a/ProcessLib/LIE/HydroMechanics/HydroMechanicsProcess.h b/ProcessLib/LIE/HydroMechanics/HydroMechanicsProcess.h
index f697820f87db3afbbb9613a81dd250b3d993986d..1c21e10699ab5aa3cd1c51c2aaf6236651818e11 100644
--- a/ProcessLib/LIE/HydroMechanics/HydroMechanicsProcess.h
+++ b/ProcessLib/LIE/HydroMechanics/HydroMechanicsProcess.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_HYDROMECHANICS_PROCESS_H_
-#define PROCESSLIB_LIE_HYDROMECHANICS_PROCESS_H_
+#pragma once
 
 #include <cassert>
 
@@ -125,5 +124,3 @@ private:
 }  // namespace HydroMechanics
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif  // PROCESSLIB_LIE_HYDROMECHANICS_PROCESS_H_
diff --git a/ProcessLib/LIE/HydroMechanics/HydroMechanicsProcessData.h b/ProcessLib/LIE/HydroMechanics/HydroMechanicsProcessData.h
index f09ff3163b65d68fe019b7cb2b5f0f394e4e299d..920a9780727ba8f09f80d60689c3e0a647b7e535 100644
--- a/ProcessLib/LIE/HydroMechanics/HydroMechanicsProcessData.h
+++ b/ProcessLib/LIE/HydroMechanics/HydroMechanicsProcessData.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_HYDROMECHANICS_HYDROMECHANICSPROCESSDATA_H_
-#define PROCESSLIB_LIE_HYDROMECHANICS_HYDROMECHANICSPROCESSDATA_H_
+#pragma once
 
 #include <memory>
 #include <Eigen/Dense>
@@ -144,5 +143,3 @@ struct HydroMechanicsProcessData
 }  // namespace HydroMechanics
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif  // PROCESSLIB_LIE_HYDROMECHANICS_HYDROMECHANICSPROCESSDATA_H_
diff --git a/ProcessLib/LIE/HydroMechanics/LocalAssembler/CreateLocalAssemblers.h b/ProcessLib/LIE/HydroMechanics/LocalAssembler/CreateLocalAssemblers.h
index 8eef1a4f2c8e90053b8ca148d6b96127fbef08de..f1a98097d80cbc3aeaa56d65b575d77b09c23e5d 100644
--- a/ProcessLib/LIE/HydroMechanics/LocalAssembler/CreateLocalAssemblers.h
+++ b/ProcessLib/LIE/HydroMechanics/LocalAssembler/CreateLocalAssemblers.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef PROCESSLIB_LIE_HYDROMECHANICS_CREATE_LOCAL_ASSEMBLERS_H_
-#define PROCESSLIB_LIE_HYDROMECHANICS_CREATE_LOCAL_ASSEMBLERS_H_
+#pragma once
 
 #include <vector>
 
@@ -99,5 +98,3 @@ void createLocalAssemblers(
 }  // namespace HydroMechanics
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif  // PROCESSLIB_LIE_HYDROMECHANICS_CREATE_LOCAL_ASSEMBLERS_H_
diff --git a/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerFracture-impl.h b/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerFracture-impl.h
index 2082ac54ed4c02a19fe33ac95cc207209d8c2e68..d016533b04cc23e3a32b94e6ec34469d64d6208e 100644
--- a/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerFracture-impl.h
+++ b/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerFracture-impl.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_HYDROMECHANICS_HYDROMECHANICSLOCALASSEMBLER_FRACTURE_IMPL_H_
-#define PROCESSLIB_LIE_HYDROMECHANICS_HYDROMECHANICSLOCALASSEMBLER_FRACTURE_IMPL_H_
+#pragma once
 
 #include "HydroMechanicsLocalAssemblerFracture.h"
 
@@ -394,5 +393,3 @@ computeSecondaryVariableConcreteWithVector(
 }  // namespace HydroMechanics
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif  // PROCESSLIB_LIE_HYDROMECHANICS_HYDROMECHANICSLOCALASSEMBLER_FRACTURE_IMPL_H_
diff --git a/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerFracture.h b/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerFracture.h
index c45a144eeb0c28b0da8cd8087105219ff1cba371..2baab2ac9409855fc67fba3fae222e0fd830d712 100644
--- a/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerFracture.h
+++ b/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerFracture.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_HYDROMECHANICS_HYDROMECHANICSLOCALASSEMBLER_FRACTURE_H_
-#define PROCESSLIB_LIE_HYDROMECHANICS_HYDROMECHANICSLOCALASSEMBLER_FRACTURE_H_
+#pragma once
 
 #include <vector>
 
@@ -118,5 +117,3 @@ private:
 }  // namespace ProcessLib
 
 #include "HydroMechanicsLocalAssemblerFracture-impl.h"
-
-#endif  // PROCESSLIB_LIE_HYDROMECHANICS_HYDROMECHANICSLOCALASSEMBLER_FRACTURE_H_
diff --git a/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerInterface.h b/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerInterface.h
index dd96b2cc835bbfa364fdc9f366bee9e3756c52c7..f30d8385a44de60f6f080676d36109e060eeffc9 100644
--- a/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerInterface.h
+++ b/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerInterface.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_HYDROMECHANICS_HYDROMECHANICSLOCALASSEMBLERINTERFACE_H_
-#define PROCESSLIB_LIE_HYDROMECHANICS_HYDROMECHANICSLOCALASSEMBLERINTERFACE_H_
+#pragma once
 
 #include <vector>
 
@@ -127,5 +126,3 @@ private:
 }  // namespace HydroMechanics
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif  // PROCESSLIB_LIE_HYDROMECHANICS_HYDROMECHANICSLOCALASSEMBLERINTERFACE_H_
diff --git a/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerMatrix-impl.h b/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerMatrix-impl.h
index e5bf3568fcf2d038549f7a478506491d7f55173d..de3dc8d583379d3d291961be89e996a627a66595 100644
--- a/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerMatrix-impl.h
+++ b/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerMatrix-impl.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_HYDROMECHANICS_HYDROMECHANICSLOCALASSEMBLER_MATRIX_IMPL_H_
-#define PROCESSLIB_LIE_HYDROMECHANICS_HYDROMECHANICSLOCALASSEMBLER_MATRIX_IMPL_H_
+#pragma once
 
 #include "HydroMechanicsLocalAssemblerMatrix.h"
 
@@ -420,5 +419,3 @@ setPressureDotOfInactiveNodes(Eigen::Ref<Eigen::VectorXd> p_dot)
 }  // namespace HydroMechanics
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif  // PROCESSLIB_LIE_HYDROMECHANICS_HYDROMECHANICSLOCALASSEMBLER_MATRIX_IMPL_H_
diff --git a/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerMatrix.h b/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerMatrix.h
index 9240c56d83b5caeec7d2f2b5b3d4d1e365c6ec2a..6538d4da9c21ac2fa4c291c9a6c0a10824363014 100644
--- a/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerMatrix.h
+++ b/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerMatrix.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_HYDROMECHANICS_HYDROMECHANICSLOCALASSEMBLER_MATRIX_H_
-#define PROCESSLIB_LIE_HYDROMECHANICS_HYDROMECHANICSLOCALASSEMBLER_MATRIX_H_
+#pragma once
 
 #include <vector>
 
@@ -130,5 +129,3 @@ protected:
 }  // namespace ProcessLib
 
 #include "HydroMechanicsLocalAssemblerMatrix-impl.h"
-
-#endif  // PROCESSLIB_LIE_HYDROMECHANICS_HYDROMECHANICSLOCALASSEMBLER_MATRIX_H_
diff --git a/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerMatrixNearFracture-impl.h b/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerMatrixNearFracture-impl.h
index 33c2561a42633579f6279bb04983bb58595b51bc..d9c1528bd38245ce299bd6d147d4f74772026ee8 100644
--- a/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerMatrixNearFracture-impl.h
+++ b/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerMatrixNearFracture-impl.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_HYDROMECHANICS_HYDROMECHANICSLOCALASSEMBLER_MATRIX_NEAR_FRACTUER_IMPL_H_
-#define PROCESSLIB_LIE_HYDROMECHANICS_HYDROMECHANICSLOCALASSEMBLER_MATRIX_NEAR_FRACTUER_IMPL_H_
+#pragma once
 
 #include "HydroMechanicsLocalAssemblerMatrixNearFracture.h"
 
@@ -165,5 +164,3 @@ computeSecondaryVariableConcreteWithVector(
 }  // namespace HydroMechanics
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif // PROCESSLIB_LIE_HYDROMECHANICS_HYDROMECHANICSLOCALASSEMBLER_MATRIX_NEAR_FRACTUER_IMPL_H_
diff --git a/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerMatrixNearFracture.h b/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerMatrixNearFracture.h
index 94f7faff395c9fcc3736a0f3bd1115e1e57689c7..45d61e9c04e1aa0788f4d3d1558fb873ae52f645 100644
--- a/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerMatrixNearFracture.h
+++ b/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerMatrixNearFracture.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_HYDROMECHANICS_HYDROMECHANICSLOCALASSEMBLER_MATRIX_NEAR_FRACTUER_H_
-#define PROCESSLIB_LIE_HYDROMECHANICS_HYDROMECHANICSLOCALASSEMBLER_MATRIX_NEAR_FRACTUER_H_
+#pragma once
 
 #include <vector>
 
@@ -80,5 +79,3 @@ private:
 }  // namespace ProcessLib
 
 #include "HydroMechanicsLocalAssemblerMatrixNearFracture-impl.h"
-
-#endif // PROCESSLIB_LIE_HYDROMECHANICS_HYDROMECHANICSLOCALASSEMBLER_MATRIX_H_
diff --git a/ProcessLib/LIE/HydroMechanics/LocalAssembler/IntegrationPointDataFracture.h b/ProcessLib/LIE/HydroMechanics/LocalAssembler/IntegrationPointDataFracture.h
index e1c7cd00f0bf0fb28b04e67b1d96f61ff2d595ef..9bab78f27908bb0bc91a28286da4a951fd889952 100644
--- a/ProcessLib/LIE/HydroMechanics/LocalAssembler/IntegrationPointDataFracture.h
+++ b/ProcessLib/LIE/HydroMechanics/LocalAssembler/IntegrationPointDataFracture.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_HYDROMECHANICS_INTEGRATIONPOINTDATAFRACTURE_H_
-#define PROCESSLIB_LIE_HYDROMECHANICS_INTEGRATIONPOINTDATAFRACTURE_H_
+#pragma once
 
 #include <Eigen/Eigen>
 
@@ -80,5 +79,3 @@ struct IntegrationPointDataFracture final
 }  // namespace HydroMechanics
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif // PROCESSLIB_LIE_HYDROMECHANICS_INTEGRATIONPOINTDATAFRACTURE_H_
diff --git a/ProcessLib/LIE/HydroMechanics/LocalAssembler/IntegrationPointDataMatrix.h b/ProcessLib/LIE/HydroMechanics/LocalAssembler/IntegrationPointDataMatrix.h
index b8bd657ba2745770412a461b6fdc757cc7baef02..dc873c00b9a5688b4bd49cca8dbbf3a0536accb7 100644
--- a/ProcessLib/LIE/HydroMechanics/LocalAssembler/IntegrationPointDataMatrix.h
+++ b/ProcessLib/LIE/HydroMechanics/LocalAssembler/IntegrationPointDataMatrix.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_HYDROMECHANICS_INTEGRATIONPOINTDATAMATRIX_H_
-#define PROCESSLIB_LIE_HYDROMECHANICS_INTEGRATIONPOINTDATAMATRIX_H_
+#pragma once
 
 #include <memory>
 #include <vector>
@@ -85,5 +84,3 @@ struct IntegrationPointDataMatrix final
 }  // namespace HydroMechanics
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif // PROCESSLIB_LIE_HYDROMECHANICS_INTEGRATIONPOINTDATAMATRIX_H_
diff --git a/ProcessLib/LIE/HydroMechanics/LocalAssembler/LocalDataInitializer.h b/ProcessLib/LIE/HydroMechanics/LocalAssembler/LocalDataInitializer.h
index b6989930870a983facfd6b5b48b66a568064721e..29f2dc6223f94eba27f2313f29e0d6645e6a8cd1 100644
--- a/ProcessLib/LIE/HydroMechanics/LocalAssembler/LocalDataInitializer.h
+++ b/ProcessLib/LIE/HydroMechanics/LocalAssembler/LocalDataInitializer.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_HYDROMECHANICS_LOCALDATAINITIALIZER_H_
-#define PROCESSLIB_LIE_HYDROMECHANICS_LOCALDATAINITIALIZER_H_
+#pragma once
 
 #include <functional>
 #include <memory>
@@ -356,5 +355,3 @@ private:
 #undef ENABLED_ELEMENT_TYPE_TRI
 #undef ENABLED_ELEMENT_TYPE_QUAD
 #undef OGS_ENABLED_ELEMENTS
-
-#endif  // PROCESSLIB_LIE_HYDROMECHANICS_LOCALDATAINITIALIZER_H_
diff --git a/ProcessLib/LIE/SmallDeformation/CreateSmallDeformationProcess.h b/ProcessLib/LIE/SmallDeformation/CreateSmallDeformationProcess.h
index 7d0c911a655aee5a8884b80ea8035e26ba671ccf..1247859c1cc4797c9adfaf6abea285a1ea3a3f9a 100644
--- a/ProcessLib/LIE/SmallDeformation/CreateSmallDeformationProcess.h
+++ b/ProcessLib/LIE/SmallDeformation/CreateSmallDeformationProcess.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_SMALLDEFORMATION_CREATESMALLDEFORMATIONPROCESS_H_
-#define PROCESSLIB_LIE_SMALLDEFORMATION_CREATESMALLDEFORMATIONPROCESS_H_
+#pragma once
 
 #include <memory>
 #include <vector>
@@ -34,5 +33,3 @@ std::unique_ptr<Process> createSmallDeformationProcess(
 }  // namespace SmallDeformation
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif  // PROCESSLIB_LIE_SMALLDEFORMATION_CREATESMALLDEFORMATIONPROCESS_H_
diff --git a/ProcessLib/LIE/SmallDeformation/LocalAssembler/CreateLocalAssemblers.h b/ProcessLib/LIE/SmallDeformation/LocalAssembler/CreateLocalAssemblers.h
index e3e1f10698f665d655a0ca6774cae4b37e1d2a02..5ecb452f78ba4f9b51b4288a3f8cf53df066cded 100644
--- a/ProcessLib/LIE/SmallDeformation/LocalAssembler/CreateLocalAssemblers.h
+++ b/ProcessLib/LIE/SmallDeformation/LocalAssembler/CreateLocalAssemblers.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef PROCESSLIB_LIE_SMALLDEFORMATION_CREATE_LOCAL_ASSEMBLERS_H_
-#define PROCESSLIB_LIE_SMALLDEFORMATION_CREATE_LOCAL_ASSEMBLERS_H_
+#pragma once
 
 #include <vector>
 
@@ -113,5 +112,3 @@ void createLocalAssemblers(
 }  // namespace SmallDeformation
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif  // PROCESSLIB_LIE_SMALLDEFORMATION_CREATE_LOCAL_ASSEMBLERS_H_
diff --git a/ProcessLib/LIE/SmallDeformation/LocalAssembler/IntegrationPointDataFracture.h b/ProcessLib/LIE/SmallDeformation/LocalAssembler/IntegrationPointDataFracture.h
index 65fc233831d8505fbcf0639d2e833b3380126b48..ce84d4edfc2c2fd090bac3a11b02645da334257e 100644
--- a/ProcessLib/LIE/SmallDeformation/LocalAssembler/IntegrationPointDataFracture.h
+++ b/ProcessLib/LIE/SmallDeformation/LocalAssembler/IntegrationPointDataFracture.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_SMALLDEFORMATION_INTEGRATIONPOINTDATAFRACTURE_H_
-#define PROCESSLIB_LIE_SMALLDEFORMATION_INTEGRATIONPOINTDATAFRACTURE_H_
+#pragma once
 
 #include <Eigen/Eigen>
 
@@ -78,5 +77,3 @@ struct IntegrationPointDataFracture final
 }  // namespace SmallDeformation
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif // PROCESSLIB_LIE_SMALLDEFORMATION_INTEGRATIONPOINTDATAFRACTURE_H_
diff --git a/ProcessLib/LIE/SmallDeformation/LocalAssembler/IntegrationPointDataMatrix.h b/ProcessLib/LIE/SmallDeformation/LocalAssembler/IntegrationPointDataMatrix.h
index 88001a73ce245ee192e57aa6be4898ea0625ce17..73b28dec804b3a13cfda093df13503071e03b367 100644
--- a/ProcessLib/LIE/SmallDeformation/LocalAssembler/IntegrationPointDataMatrix.h
+++ b/ProcessLib/LIE/SmallDeformation/LocalAssembler/IntegrationPointDataMatrix.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_SMALLDEFORMATION_INTEGRATIONPOINTDATAMATRIX_H_
-#define PROCESSLIB_LIE_SMALLDEFORMATION_INTEGRATIONPOINTDATAMATRIX_H_
+#pragma once
 
 #include <memory>
 #include <vector>
@@ -74,5 +73,3 @@ struct IntegrationPointDataMatrix final
 }  // namespace SmallDeformation
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif // PROCESSLIB_LIE_SMALLDEFORMATION_INTEGRATIONPOINTDATAMATRIX_H_
diff --git a/ProcessLib/LIE/SmallDeformation/LocalAssembler/LocalAssemblerDataFracture.h b/ProcessLib/LIE/SmallDeformation/LocalAssembler/LocalAssemblerDataFracture.h
index 4126d0460d1a9b365e7f10e413e36b9cb3af2b59..f87d2fcf335101ee9c05a0f8477d846fb4d6092e 100644
--- a/ProcessLib/LIE/SmallDeformation/LocalAssembler/LocalAssemblerDataFracture.h
+++ b/ProcessLib/LIE/SmallDeformation/LocalAssembler/LocalAssemblerDataFracture.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_SMALLDEFORMATION_LOCALASSEMBLERDATA_FRACTURE_H_
-#define PROCESSLIB_LIE_SMALLDEFORMATION_LOCALASSEMBLERDATA_FRACTURE_H_
+#pragma once
 
 #include "SmallDeformationLocalAssemblerFracture.h"
 
@@ -47,5 +46,3 @@ public:
 }  // namespace SmallDeformation
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif  // PROCESSLIB_LIE_SMALLDEFORMATION_LOCALASSEMBLERDATA_FRACTURE_H_
diff --git a/ProcessLib/LIE/SmallDeformation/LocalAssembler/LocalAssemblerDataMatrix.h b/ProcessLib/LIE/SmallDeformation/LocalAssembler/LocalAssemblerDataMatrix.h
index 39136ad7f51eed70729e5904cd7922ce9102c7b7..ff56709e68aec10cade9da69bb13ba0619fe014e 100644
--- a/ProcessLib/LIE/SmallDeformation/LocalAssembler/LocalAssemblerDataMatrix.h
+++ b/ProcessLib/LIE/SmallDeformation/LocalAssembler/LocalAssemblerDataMatrix.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_SMALLDEFORMATION_LOCALASSEMBLERDATA_H_
-#define PROCESSLIB_LIE_SMALLDEFORMATION_LOCALASSEMBLERDATA_H_
+#pragma once
 
 #include "SmallDeformationLocalAssemblerMatrix.h"
 
@@ -46,5 +45,3 @@ public:
 }  // namespace SmallDeformation
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif  // PROCESSLIB_LIE_SMALLDEFORMATION_LOCALASSEMBLERDATA_H_
diff --git a/ProcessLib/LIE/SmallDeformation/LocalAssembler/LocalAssemblerDataMatrixNearFracture.h b/ProcessLib/LIE/SmallDeformation/LocalAssembler/LocalAssemblerDataMatrixNearFracture.h
index 9aff764ade38334a5e1cf2c719c7235c87bab275..4031c89c55cbbd1789af757b1193c28e63731ce4 100644
--- a/ProcessLib/LIE/SmallDeformation/LocalAssembler/LocalAssemblerDataMatrixNearFracture.h
+++ b/ProcessLib/LIE/SmallDeformation/LocalAssembler/LocalAssemblerDataMatrixNearFracture.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_SMALLDEFORMATION_LOCALASSEMBLERDATAMATRIXNEARFRACTURE_H_
-#define PROCESSLIB_LIE_SMALLDEFORMATION_LOCALASSEMBLERDATAMATRIXNEARFRACTURE_H_
+#pragma once
 
 #include "SmallDeformationLocalAssemblerMatrixNearFracture.h"
 
@@ -48,5 +47,3 @@ public:
 }  // namespace SmallDeformation
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif // PROCESSLIB_LIE_SMALLDEFORMATION_LOCALASSEMBLERDATAMATRIXNEARFRACTURE_H_
diff --git a/ProcessLib/LIE/SmallDeformation/LocalAssembler/LocalDataInitializer.h b/ProcessLib/LIE/SmallDeformation/LocalAssembler/LocalDataInitializer.h
index 1680d53fe4a2f18885c96a83dc20c85092566a75..02f726adecbc04c59d323cdff9374af1ce55a64e 100644
--- a/ProcessLib/LIE/SmallDeformation/LocalAssembler/LocalDataInitializer.h
+++ b/ProcessLib/LIE/SmallDeformation/LocalAssembler/LocalDataInitializer.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_SMALLDEFORMATION_LOCALDATAINITIALIZER_H_
-#define PROCESSLIB_LIE_SMALLDEFORMATION_LOCALDATAINITIALIZER_H_
+#pragma once
 
 #include <functional>
 #include <memory>
@@ -416,5 +415,3 @@ private:
 #undef ENABLED_ELEMENT_TYPE_TRI
 #undef ENABLED_ELEMENT_TYPE_QUAD
 #undef OGS_ENABLED_ELEMENTS
-
-#endif  // PROCESSLIB_LIE_SMALLDEFORMATION_LOCALDATAINITIALIZER_H_
diff --git a/ProcessLib/LIE/SmallDeformation/LocalAssembler/SecondaryData.h b/ProcessLib/LIE/SmallDeformation/LocalAssembler/SecondaryData.h
index 0987193b90914d79d91ce535c0d16d53f6fca837..3fccea11b2c1733c8a214750e3db7045596060b4 100644
--- a/ProcessLib/LIE/SmallDeformation/LocalAssembler/SecondaryData.h
+++ b/ProcessLib/LIE/SmallDeformation/LocalAssembler/SecondaryData.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_SMALLDEFORMATION_SECONDARY_DATA_H_
-#define PROCESSLIB_LIE_SMALLDEFORMATION_SECONDARY_DATA_H_
+#pragma once
 
 namespace ProcessLib
 {
@@ -28,5 +27,3 @@ struct SecondaryData
 }  // namespace SmallDeformation
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif  // PROCESSLIB_LIE_SMALLDEFORMATION_SECONDARY_DATA_H_
diff --git a/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerFracture-impl.h b/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerFracture-impl.h
index ac0cdce26ff6eff81138427f353b131965b898b9..50ce1cbfae3df8d5284c47bdca05219b4f03353e 100644
--- a/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerFracture-impl.h
+++ b/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerFracture-impl.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATIONLOCALASSEMBLER_FRACTURE_IMPL_H_
-#define PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATIONLOCALASSEMBLER_FRACTURE_IMPL_H_
+#pragma once
 
 #include "SmallDeformationLocalAssemblerFracture.h"
 
@@ -178,5 +177,3 @@ postTimestepConcrete(std::vector<double> const& /*local_x*/)
 }  // namespace SmallDeformation
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif  // PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATIONLOCALASSEMBLER_FRACTURE_IMPL_H_
diff --git a/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerFracture.h b/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerFracture.h
index 744f7e79c15d3ee2965cf9ba30635fd91b76fa29..04a1c8dd87cd2b558803aafd41803ef6b8e1b883 100644
--- a/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerFracture.h
+++ b/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerFracture.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATIONLOCALASSEMBLER_FRACTURE_H_
-#define PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATIONLOCALASSEMBLER_FRACTURE_H_
+#pragma once
 
 #include <vector>
 
@@ -166,5 +165,3 @@ private:
 }  // namespace ProcessLib
 
 #include "SmallDeformationLocalAssemblerFracture-impl.h"
-
-#endif  // PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATIONLOCALASSEMBLER_FRACTURE_H_
diff --git a/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerInterface.h b/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerInterface.h
index edea655e68a944b8a4dfa5b3efac4c865ed327eb..b082fa43bded15cf9a55af12a1ecde0dfaf14c0d 100644
--- a/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerInterface.h
+++ b/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerInterface.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATIONLOCALASSEMBLERINTERFACE_H_
-#define PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATIONLOCALASSEMBLERINTERFACE_H_
+#pragma once
 
 #include <vector>
 
@@ -114,5 +113,3 @@ private:
 }  // namespace SmallDeformation
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif  // PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATIONLOCALASSEMBLERINTERFACE_H_
diff --git a/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerMatrix-impl.h b/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerMatrix-impl.h
index 30cef5babbe0ccab5da8e4e3ac04086ecbdf8f51..0a49385384f39380e4e4ae3404e8139c9185bbc1 100644
--- a/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerMatrix-impl.h
+++ b/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerMatrix-impl.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATIONLOCALASSEMBLER_MATRIX_IMPL_H_
-#define PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATIONLOCALASSEMBLER_MATRIX_IMPL_H_
+#pragma once
 
 #include "SmallDeformationLocalAssemblerMatrix.h"
 
@@ -196,5 +195,3 @@ postTimestepConcrete(std::vector<double> const& /*local_x*/)
 }  // namespace SmallDeformation
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif  // PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATIONLOCALASSEMBLER_MATRIX_IMPL_H_
diff --git a/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerMatrix.h b/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerMatrix.h
index 1a1f3c903f8c428a7faa791327ac134d07076b63..ded00cf999ba85a472b9095f810ced5b11a840f0 100644
--- a/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerMatrix.h
+++ b/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerMatrix.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATIONLOCALASSEMBLER_MATRIX_H_
-#define PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATIONLOCALASSEMBLER_MATRIX_H_
+#pragma once
 
 #include <vector>
 
@@ -172,5 +171,3 @@ private:
 }  // namespace ProcessLib
 
 #include "SmallDeformationLocalAssemblerMatrix-impl.h"
-
-#endif  // PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATIONLOCALASSEMBLER_MATRIX_H_
diff --git a/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerMatrixNearFracture-impl.h b/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerMatrixNearFracture-impl.h
index dc1da39942ca363e24023897c9c15c55ea698f3d..75d9897a41defc21d831bfd890d5e2ab6c12b973 100644
--- a/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerMatrixNearFracture-impl.h
+++ b/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerMatrixNearFracture-impl.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATIONLOCALASSEMBLER_MATRIX_NEAR_FRACTUER_IMPL_H_
-#define PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATIONLOCALASSEMBLER_MATRIX_NEAR_FRACTUER_IMPL_H_
+#pragma once
 
 #include "SmallDeformationLocalAssemblerMatrixNearFracture.h"
 
@@ -282,5 +281,3 @@ postTimestepConcrete(std::vector<double> const& /*local_x*/)
 }  // namespace SmallDeformation
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif // PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATIONLOCALASSEMBLER_MATRIX_NEAR_FRACTUER_IMPL_H_
diff --git a/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerMatrixNearFracture.h b/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerMatrixNearFracture.h
index 0999833bba103da4e8814fd29b11bdeb14d677d0..23ce29b5202b72addd742055a1f4267d1ad3cf3b 100644
--- a/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerMatrixNearFracture.h
+++ b/ProcessLib/LIE/SmallDeformation/LocalAssembler/SmallDeformationLocalAssemblerMatrixNearFracture.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATIONLOCALASSEMBLER_MATRIX_NEAR_FRACTUER_H_
-#define PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATIONLOCALASSEMBLER_MATRIX_NEAR_FRACTUER_H_
+#pragma once
 
 #include <vector>
 
@@ -176,5 +175,3 @@ private:
 }  // namespace ProcessLib
 
 #include "SmallDeformationLocalAssemblerMatrixNearFracture-impl.h"
-
-#endif // PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATIONLOCALASSEMBLER_MATRIX_H_
diff --git a/ProcessLib/LIE/SmallDeformation/SmallDeformationProcess-fwd.h b/ProcessLib/LIE/SmallDeformation/SmallDeformationProcess-fwd.h
index 654f600dcca51c2a5fae85fdeceb6584f34f7650..f010dfb99b3e4d1607a8d6527eedb35e5a64ae37 100644
--- a/ProcessLib/LIE/SmallDeformation/SmallDeformationProcess-fwd.h
+++ b/ProcessLib/LIE/SmallDeformation/SmallDeformationProcess-fwd.h
@@ -7,11 +7,8 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATION_PROCESS_FWD_H_
-#define PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATION_PROCESS_FWD_H_
+#pragma once
 
 #include "SmallDeformationProcess.h"
 
 extern template class ProcessLib::LIE::SmallDeformation::SmallDeformationProcess<2>;
-
-#endif  // PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATION_PROCESS_FWD_H_
diff --git a/ProcessLib/LIE/SmallDeformation/SmallDeformationProcess.h b/ProcessLib/LIE/SmallDeformation/SmallDeformationProcess.h
index 4ce7d67a4d956a66f0c5ced461d4cb9a5f99f2f9..3a0e40d93b5f460b4d007ad2f32c2eb311ac3f5c 100644
--- a/ProcessLib/LIE/SmallDeformation/SmallDeformationProcess.h
+++ b/ProcessLib/LIE/SmallDeformation/SmallDeformationProcess.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATION_PROCESS_H_
-#define PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATION_PROCESS_H_
+#pragma once
 
 #include <cassert>
 
@@ -126,5 +125,3 @@ private:
 }  // namespace SmallDeformation
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif  // PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATION_PROCESS_H_
diff --git a/ProcessLib/LIE/SmallDeformation/SmallDeformationProcessData.h b/ProcessLib/LIE/SmallDeformation/SmallDeformationProcessData.h
index 52e7ca06e0ce339ac6d2c5bc4171dfb66b264fa5..35ecd8cf8a3d3f85284a5df90c531dd338f61835 100644
--- a/ProcessLib/LIE/SmallDeformation/SmallDeformationProcessData.h
+++ b/ProcessLib/LIE/SmallDeformation/SmallDeformationProcessData.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATIONPROCESSDATA_H_
-#define PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATIONPROCESSDATA_H_
+#pragma once
 
 #include <memory>
 
@@ -87,5 +86,3 @@ struct SmallDeformationProcessData
 }  // namespace SmallDeformation
 }  // namespace LIE
 }  // namespace ProcessLib
-
-#endif  // PROCESSLIB_LIE_SMALLDEFORMATION_SMALLDEFORMATIONPROCESSDATA_H_
diff --git a/ProcessLib/LiquidFlow/CreateLiquidFlowProcess.h b/ProcessLib/LiquidFlow/CreateLiquidFlowProcess.h
index 752208b039da766e0a1692892c2b7ea86b351fe3..3e9ed9436e12c65a8d6a40ce5e3ef864c240cc20 100644
--- a/ProcessLib/LiquidFlow/CreateLiquidFlowProcess.h
+++ b/ProcessLib/LiquidFlow/CreateLiquidFlowProcess.h
@@ -10,8 +10,7 @@
  * Created on August 19, 2016, 1:30 PM
  */
 
-#ifndef OGS_CREATELIQUIDFLOWPROCESS_H
-#define OGS_CREATELIQUIDFLOWPROCESS_H
+#pragma once
 
 #include <memory>
 #include "ProcessLib/Process.h"
@@ -29,5 +28,3 @@ std::unique_ptr<Process> createLiquidFlowProcess(
     BaseLib::ConfigTree const& config);
 }  // end of namespace
 }  // end of namespace
-
-#endif /* CREATELIQUIDFLOWPROCESS_H */
diff --git a/ProcessLib/LiquidFlow/LiquidFlowLocalAssembler-impl.h b/ProcessLib/LiquidFlow/LiquidFlowLocalAssembler-impl.h
index 98ee0cbc783fdc141e9c95482ac90f0d3248344c..d7a984a2b459381adbe634e467e54fbf15fca344 100644
--- a/ProcessLib/LiquidFlow/LiquidFlowLocalAssembler-impl.h
+++ b/ProcessLib/LiquidFlow/LiquidFlowLocalAssembler-impl.h
@@ -10,8 +10,7 @@
  * Created on August 19, 2016, 2:28 PM
  */
 
-#ifndef OGS_LIQUIDFLOWLOCALASSEMBLER_IMPL_H
-#define OGS_LIQUIDFLOWLOCALASSEMBLER_IMPL_H
+#pragma once
 
 #include "LiquidFlowLocalAssembler.h"
 
@@ -257,5 +256,3 @@ void LiquidFlowLocalAssembler<ShapeFunction, IntegrationMethod, GlobalDim>::
 
 }  // end of namespace
 }  // end of namespace
-
-#endif /* OGS_LIQUIDFLOWLOCALASSEMBLER_IMPL_H */
diff --git a/ProcessLib/LiquidFlow/LiquidFlowLocalAssembler.h b/ProcessLib/LiquidFlow/LiquidFlowLocalAssembler.h
index 1ec901fe8e698b806ce647b123964aef17cc9b98..d1a5db31306aa0724e2cfe623ddd026a08b3c33a 100644
--- a/ProcessLib/LiquidFlow/LiquidFlowLocalAssembler.h
+++ b/ProcessLib/LiquidFlow/LiquidFlowLocalAssembler.h
@@ -10,8 +10,7 @@
  * Created on August 19, 2016, 2:28 PM
  */
 
-#ifndef OGS_LIQUIDFLOWLOCALASSEMBLER_H
-#define OGS_LIQUIDFLOWLOCALASSEMBLER_H
+#pragma once
 
 #include <vector>
 
@@ -195,5 +194,3 @@ private:
 }  // end of namespace
 
 #include "LiquidFlowLocalAssembler-impl.h"
-
-#endif /* LIQUIDFLOWLOCALASSEMBLER_H */
diff --git a/ProcessLib/LiquidFlow/LiquidFlowMaterialProperties.h b/ProcessLib/LiquidFlow/LiquidFlowMaterialProperties.h
index e526081cb9f413df13774e068ee264f61fec6312..923a9adb358ac07e7062170109dd9404efbc51bb 100644
--- a/ProcessLib/LiquidFlow/LiquidFlowMaterialProperties.h
+++ b/ProcessLib/LiquidFlow/LiquidFlowMaterialProperties.h
@@ -10,8 +10,7 @@
  * Created on August 18, 2016, 11:03 AM
  */
 
-#ifndef OGS_LIQUIDFLOWMATERIALPROPERTIES_H
-#define OGS_LIQUIDFLOWMATERIALPROPERTIES_H
+#pragma once
 
 #include <memory>
 
@@ -106,4 +105,3 @@ private:
 
 }  // end of namespace
 }  // end of namespace
-#endif /* LIQUIDFLOWMATERIALPROPERTIES_H */
diff --git a/ProcessLib/LiquidFlow/LiquidFlowProcess.h b/ProcessLib/LiquidFlow/LiquidFlowProcess.h
index d6e8c6ea87609ee37aea57e1827199615435138c..9e403396cd3f8b6b58b0b3864f49f1c14a7f6979 100644
--- a/ProcessLib/LiquidFlow/LiquidFlowProcess.h
+++ b/ProcessLib/LiquidFlow/LiquidFlowProcess.h
@@ -10,8 +10,7 @@
  * Created on August 19, 2016, 1:38 PM
  */
 
-#ifndef OGS_LIQUIDFLOWPROCESS_H
-#define OGS_LIQUIDFLOWPROCESS_H
+#pragma once
 
 #include "NumLib/DOF/LocalToGlobalIndexMap.h"
 #include "ProcessLib/Process.h"
@@ -97,5 +96,3 @@ private:
 
 }  // end of namespace
 }  // end of namespace
-
-#endif /* LIQUIDFLOWPROCESS_H */
diff --git a/ProcessLib/LocalAssemblerInterface.h b/ProcessLib/LocalAssemblerInterface.h
index c4e0fe20f0c68f382724bfeec300e24fa3effdeb..8176485f679d31959f251bc8d869ac0691917ed9 100644
--- a/ProcessLib/LocalAssemblerInterface.h
+++ b/ProcessLib/LocalAssemblerInterface.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LOCALASSEMBLERINTERFACE_H
-#define PROCESSLIB_LOCALASSEMBLERINTERFACE_H
+#pragma once
 
 #include "NumLib/NumericsConfig.h"
 #include "MathLib/Point3d.h"
@@ -80,5 +79,3 @@ private:
 };
 
 } // namespace ProcessLib
-
-#endif // PROCESSLIB_LOCALASSEMBLERINTERFACE_H
diff --git a/ProcessLib/LocalAssemblerTraits.h b/ProcessLib/LocalAssemblerTraits.h
index 7e17a30bdcdfeedd4f2b000f7b537d27fa975af2..727f0836da19607a15dc35398afb80b717c90e0c 100644
--- a/ProcessLib/LocalAssemblerTraits.h
+++ b/ProcessLib/LocalAssemblerTraits.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_LOCALASSEMBLERTRAITS_H
-#define PROCESSLIB_LOCALASSEMBLERTRAITS_H
+#pragma once
 
 namespace ProcessLib
 {
@@ -230,5 +229,3 @@ static_assert(OGS_EIGEN_DYNAMIC_SHAPE_MATRICES_FLAG == 1,
 #endif
 
 }
-
-#endif // PROCESSLIB_LOCALASSEMBLERTRAITS_H
diff --git a/ProcessLib/Output.h b/ProcessLib/Output.h
index f94490ffe49800e5819b348d2860f0e1fa7d631b..766c5d26ee5c9f91b9c1d5bc605579868a91734f 100644
--- a/ProcessLib/Output.h
+++ b/ProcessLib/Output.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_OUTPUT_H
-#define PROCESSLIB_OUTPUT_H
+#pragma once
 
 #include "BaseLib/ConfigTree.h"
 #include "MeshLib/IO/VtkIO/PVDFile.h"
@@ -99,5 +98,3 @@ private:
 };
 
 }
-
-#endif // PROCESSLIB_OUTPUT_H
diff --git a/ProcessLib/Parameter/ConstantParameter.h b/ProcessLib/Parameter/ConstantParameter.h
index a7fe02b503e50d09093c6c2f9668a009609df12b..d754e75727db8b7f54769a1027c473b90890d943 100644
--- a/ProcessLib/Parameter/ConstantParameter.h
+++ b/ProcessLib/Parameter/ConstantParameter.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_CONSTANTPARAMETER_H
-#define PROCESSLIB_CONSTANTPARAMETER_H
+#pragma once
 
 #include "Parameter.h"
 
@@ -54,5 +53,3 @@ std::unique_ptr<ParameterBase> createConstantParameter(
     std::string const& name, BaseLib::ConfigTree const& config);
 
 }  // ProcessLib
-
-#endif  // PROCESSLIB_CONSTANTPARAMETER_H
diff --git a/ProcessLib/Parameter/CurveScaledParameter.h b/ProcessLib/Parameter/CurveScaledParameter.h
index 11f3883ad463c2bbd0c1c0c85e9eb2bec7aba3d9..57d39ced101bf62bf0c9268adf55af274d4d691a 100644
--- a/ProcessLib/Parameter/CurveScaledParameter.h
+++ b/ProcessLib/Parameter/CurveScaledParameter.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_CURVESCALEDPARAMETER_H
-#define PROCESSLIB_CURVESCALEDPARAMETER_H
+#pragma once
 
 #include <map>
 #include "MathLib/InterpolationAlgorithms/PiecewiseLinearInterpolation.h"
@@ -71,5 +70,3 @@ std::unique_ptr<ParameterBase> createCurveScaledParameter(
         curves);
 
 }  // ProcessLib
-
-#endif  // PROCESSLIB_CURVESCALEDPARAMETER_H
diff --git a/ProcessLib/Parameter/GroupBasedParameter.h b/ProcessLib/Parameter/GroupBasedParameter.h
index bc4ee771cc4606d4345d87e4d9ded6f54aa2e934..aa336588c2d2c6fb8f8687f88e9982b8b8699d09 100644
--- a/ProcessLib/Parameter/GroupBasedParameter.h
+++ b/ProcessLib/Parameter/GroupBasedParameter.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_GROUPBASEDPARAMETER_H_
-#define PROCESSLIB_GROUPBASEDPARAMETER_H_
+#pragma once
 
 #include "BaseLib/Error.h"
 #include "MeshLib/PropertyVector.h"
@@ -91,5 +90,3 @@ std::unique_ptr<ParameterBase> createGroupBasedParameter(
     MeshLib::Mesh const& mesh);
 
 }  // ProcessLib
-
-#endif // PROCESSLIB_GROUPBASEDPARAMETER_H_
diff --git a/ProcessLib/Parameter/MeshElementParameter.h b/ProcessLib/Parameter/MeshElementParameter.h
index 2d0b7c04830bba1ac31072e3056003942819b20a..966fe7dd9bb7de37901c3ca5ad80a6bda7661adc 100644
--- a/ProcessLib/Parameter/MeshElementParameter.h
+++ b/ProcessLib/Parameter/MeshElementParameter.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_MESHELEMENTPARAMETER_H
-#define PROCESSLIB_MESHELEMENTPARAMETER_H
+#pragma once
 
 #include "Parameter.h"
 
@@ -60,5 +59,3 @@ std::unique_ptr<ParameterBase> createMeshElementParameter(
     MeshLib::Mesh const& mesh);
 
 }  // ProcessLib
-
-#endif  // PROCESSLIB_MESHELEMENTPARAMETER_H
diff --git a/ProcessLib/Parameter/MeshNodeParameter.h b/ProcessLib/Parameter/MeshNodeParameter.h
index b181aca1f95adcc3a56c8131c184740d9ac2065e..a6d1da482be3c28dcefc98dad73046b9112a3282 100644
--- a/ProcessLib/Parameter/MeshNodeParameter.h
+++ b/ProcessLib/Parameter/MeshNodeParameter.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_MESHNODEPARAMETER_H
-#define PROCESSLIB_MESHNODEPARAMETER_H
+#pragma once
 
 #include "Parameter.h"
 
@@ -60,5 +59,3 @@ std::unique_ptr<ParameterBase> createMeshNodeParameter(
     MeshLib::Mesh const& mesh);
 
 }  // ProcessLib
-
-#endif  // PROCESSLIB_MESHNODEPARAMETER_H
diff --git a/ProcessLib/Parameter/Parameter.h b/ProcessLib/Parameter/Parameter.h
index c44c31189855c6047e32d9df25278a057608827f..b9a818944143444c4325321616dcfca2f1771cba 100644
--- a/ProcessLib/Parameter/Parameter.h
+++ b/ProcessLib/Parameter/Parameter.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_PARAMETER_H_
-#define PROCESS_LIB_PARAMETER_H_
+#pragma once
 
 #include <map>
 #include <memory>
@@ -87,5 +86,3 @@ std::unique_ptr<ParameterBase> createParameter(
         curves);
 
 }  // namespace ProcessLib
-
-#endif  // PROCESS_LIB_PARAMETER_H_
diff --git a/ProcessLib/Parameter/SpatialPosition.h b/ProcessLib/Parameter/SpatialPosition.h
index ca2ceac8a253682deddf48c8dd4fe860a1cb84cb..417a487747a4835a97a8f3e5a4bb4f076394af62 100644
--- a/ProcessLib/Parameter/SpatialPosition.h
+++ b/ProcessLib/Parameter/SpatialPosition.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_SPATIALPOSITION_H
-#define PROCESSLIB_SPATIALPOSITION_H
+#pragma once
 
 #include <boost/optional.hpp>
 #include "MathLib/TemplatePoint.h"
@@ -89,5 +88,3 @@ private:
 };
 
 }  // ProcessLib
-
-#endif  // PROCESSLIB_SPATIALPOSITION_H
diff --git a/ProcessLib/Process.h b/ProcessLib/Process.h
index ffdc235e18017918f4a51ee2dfa96cdc51d35692..fcd4b82ec029f6b475d0f27ef04fd90680f8e9cb 100644
--- a/ProcessLib/Process.h
+++ b/ProcessLib/Process.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_PROCESS_H_
-#define PROCESS_LIB_PROCESS_H_
+#pragma once
 
 #include "NumLib/ODESolver/NonlinearSolver.h"
 #include "NumLib/ODESolver/ODESystem.h"
@@ -206,5 +205,3 @@ private:
 };
 
 }  // namespace ProcessLib
-
-#endif  // PROCESS_LIB_PROCESS_H_
diff --git a/ProcessLib/ProcessOutput.h b/ProcessLib/ProcessOutput.h
index f1559b3c892e6e42243fba1281f50c5e4388c4db..f0bd16bda5741f74bf7bce83f122bb376c0727a2 100644
--- a/ProcessLib/ProcessOutput.h
+++ b/ProcessLib/ProcessOutput.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_PROCESSOUTPUT_H
-#define PROCESSLIB_PROCESSOUTPUT_H
+#pragma once
 
 #include "ProcessVariable.h"
 #include "SecondaryVariable.h"
@@ -42,6 +41,3 @@ void doProcessOutput(
         ProcessOutput const& process_output);
 
 } // ProcessLib
-
-
-#endif // PROCESSLIB_PROCESSOUTPUT_H
diff --git a/ProcessLib/ProcessVariable.h b/ProcessLib/ProcessVariable.h
index 0bcbd1f4847f617038f2e544a305cec07ebeae1e..56aa3c9e797d31bd4e4223d4c1c417e4d2d45194 100644
--- a/ProcessLib/ProcessVariable.h
+++ b/ProcessLib/ProcessVariable.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_PROCESS_VARIABLE_H_
-#define PROCESS_LIB_PROCESS_VARIABLE_H_
+#pragma once
 
 #include "ProcessLib/BoundaryCondition/BoundaryCondition.h"
 #include "ProcessLib/BoundaryCondition/BoundaryConditionConfig.h"
@@ -91,5 +90,3 @@ private:
 };
 
 }  // namespace ProcessLib
-
-#endif  // PROCESS_LIB_PROCESS_VARIABLE_H_
diff --git a/ProcessLib/RichardsFlow/CreateRichardsFlowProcess.h b/ProcessLib/RichardsFlow/CreateRichardsFlowProcess.h
index 3ed760086adffac28bbcd29bf1e0893832a160a4..b97b943af25909185360c418c672f74d4d03ac2a 100644
--- a/ProcessLib/RichardsFlow/CreateRichardsFlowProcess.h
+++ b/ProcessLib/RichardsFlow/CreateRichardsFlowProcess.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_CREATE_RICHARDSFLOWPROCESS_H_
-#define PROCESS_LIB_CREATE_RICHARDSFLOWPROCESS_H_
+#pragma once
 
 #include <memory>
 #include "ProcessLib/Process.h"
@@ -29,5 +28,3 @@ std::unique_ptr<Process> createRichardsFlowProcess(
         curves);
 }  // namespace RichardsFlow
 }  // namespace ProcessLib
-
-#endif  // PROCESS_LIB_CREATE_RICHARDSFLOWPROCESS_H_
diff --git a/ProcessLib/RichardsFlow/RichardsFlowFEM.h b/ProcessLib/RichardsFlow/RichardsFlowFEM.h
index ce1d68a53bf203bc7440c69ad692e1ef39da0608..55cae850bef50324674b62d96d4c19fd88b60655 100644
--- a/ProcessLib/RichardsFlow/RichardsFlowFEM.h
+++ b/ProcessLib/RichardsFlow/RichardsFlowFEM.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_RICHARDSFLOW_FEM_H_
-#define PROCESS_LIB_RICHARDSFLOW_FEM_H_
+#pragma once
 
 #include <vector>
 
@@ -188,5 +187,3 @@ private:
 
 }  // namespace RichardsFlow
 }  // namespace ProcessLib
-
-#endif  // PROCESS_LIB_RichardsFlow_FEM_H_
diff --git a/ProcessLib/RichardsFlow/RichardsFlowProcess.h b/ProcessLib/RichardsFlow/RichardsFlowProcess.h
index 547fa3c7dc10d22134c7d0eeb71be93668edddbc..954ba7af7b8640a461a9314b2251d04ef13679e1 100644
--- a/ProcessLib/RichardsFlow/RichardsFlowProcess.h
+++ b/ProcessLib/RichardsFlow/RichardsFlowProcess.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_RICHARDSFLOWPROCESS_H_
-#define PROCESS_LIB_RICHARDSFLOWPROCESS_H_
+#pragma once
 
 #include "NumLib/Extrapolation/LocalLinearLeastSquaresExtrapolator.h"
 #include "ProcessLib/Process.h"
@@ -65,5 +64,3 @@ private:
 
 }  // namespace RichardsFlow
 }  // namespace ProcessLib
-
-#endif  // PROCESS_LIB_RICHARDSFLOWPROCESS_H_
diff --git a/ProcessLib/RichardsFlow/RichardsFlowProcessData.h b/ProcessLib/RichardsFlow/RichardsFlowProcessData.h
index 92f6daef0c87d849959d3980ad5d941fbc330dc1..4d7ea9ebb51750fc428e8dd9bacd576b557c3f1d 100644
--- a/ProcessLib/RichardsFlow/RichardsFlowProcessData.h
+++ b/ProcessLib/RichardsFlow/RichardsFlowProcessData.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_RICHARDSFLOW_RICHARDSFLOWPROCESSDATA_H
-#define PROCESSLIB_RICHARDSFLOW_RICHARDSFLOWPROCESSDATA_H
+#pragma once
 
 namespace MeshLib
 {
@@ -85,5 +84,3 @@ struct RichardsFlowProcessData
 
 }  // namespace RichardsFlow
 }  // namespace ProcessLib
-
-#endif  // PROCESSLIB_RichardsFlow_RichardsFlowPROCESSDATA_H
diff --git a/ProcessLib/SecondaryVariable.h b/ProcessLib/SecondaryVariable.h
index 3e1ba69aa13cf197bb429875d3aaaebfaa5ae74b..de54dec8710a2c0378523a65a3ec576553e3ce02 100644
--- a/ProcessLib/SecondaryVariable.h
+++ b/ProcessLib/SecondaryVariable.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_SECONDARY_VARIABLE_H
-#define PROCESSLIB_SECONDARY_VARIABLE_H
+#pragma once
 
 #include "BaseLib/ConfigTree.h"
 #include "BaseLib/uniqueInsert.h"
@@ -181,5 +180,3 @@ SecondaryVariableFunctions makeExtrapolator(
 }
 
 }  // namespace ProcessLib
-
-#endif // PROCESSLIB_SECONDARY_VARIABLE_H
diff --git a/ProcessLib/SecondaryVariableContext.h b/ProcessLib/SecondaryVariableContext.h
index cbc8dcf83deb2ad67a08d2fa75b9717ac824a9a6..717db74124fd7e5d0330004b17d932972090d904 100644
--- a/ProcessLib/SecondaryVariableContext.h
+++ b/ProcessLib/SecondaryVariableContext.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_SECONDARYVARIABLECONTEXT_H
-#define PROCESSLIB_SECONDARYVARIABLECONTEXT_H
+#pragma once
 
 namespace ProcessLib
 {
@@ -27,5 +26,3 @@ public:
 };
 
 }  // namespace ProcessLib
-
-#endif  // PROCESSLIB_SECONDARYVARIABLECONTEXT_H
diff --git a/ProcessLib/SmallDeformation/CreateLocalAssemblers.h b/ProcessLib/SmallDeformation/CreateLocalAssemblers.h
index 4482baccbf2dd80ee8a18220099c9661233c5191..efeb85943ba80af7017227e2f348385009f27776 100644
--- a/ProcessLib/SmallDeformation/CreateLocalAssemblers.h
+++ b/ProcessLib/SmallDeformation/CreateLocalAssemblers.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef PROCESSLIB_SMALLDEFORMATION_CREATE_LOCAL_ASSEMBLERS_H_
-#define PROCESSLIB_SMALLDEFORMATION_CREATE_LOCAL_ASSEMBLERS_H_
+#pragma once
 
 #include <vector>
 
@@ -102,5 +101,3 @@ void createLocalAssemblers(
 }  // SmallDeformation
 
 }  // ProcessLib
-
-#endif  // PROCESSLIB_SMALLDEFORMATION_CREATE_LOCAL_ASSEMBLERS_H_
diff --git a/ProcessLib/SmallDeformation/CreateSmallDeformationProcess.h b/ProcessLib/SmallDeformation/CreateSmallDeformationProcess.h
index 5908e3db138d741b1492188b12ae2ac79e759498..45d2a6e7638f992917f6c557dddd18e3fdb7777a 100644
--- a/ProcessLib/SmallDeformation/CreateSmallDeformationProcess.h
+++ b/ProcessLib/SmallDeformation/CreateSmallDeformationProcess.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_CREATESMALLDEFORMATIONPROCESS_H_
-#define PROCESS_LIB_CREATESMALLDEFORMATIONPROCESS_H_
+#pragma once
 
 #include "MaterialLib/SolidModels/CreateLubby2.h"
 #include "ProcessLib/Process.h"
@@ -28,5 +27,3 @@ std::unique_ptr<Process> createSmallDeformationProcess(
 
 }  // namespace SmallDeformation
 }  // namespace ProcessLib
-
-#endif  // PROCESS_LIB_CREATESMALLDEFORMATIONPROCESS_H_
diff --git a/ProcessLib/SmallDeformation/LocalDataInitializer.h b/ProcessLib/SmallDeformation/LocalDataInitializer.h
index 3a2e388593e632816b3f0c0800de17e9baba3f02..d763ffdb2963d0b20e1bc5b5bb143d884cdf1c47 100644
--- a/ProcessLib/SmallDeformation/LocalDataInitializer.h
+++ b/ProcessLib/SmallDeformation/LocalDataInitializer.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_SMALLDEFORMATION_LOCALDATAINITIALIZER_H_
-#define PROCESSLIB_SMALLDEFORMATION_LOCALDATAINITIALIZER_H_
+#pragma once
 
 #include <functional>
 #include <memory>
@@ -303,5 +302,3 @@ private:
 #undef ENABLED_ELEMENT_TYPE_TRI
 #undef ENABLED_ELEMENT_TYPE_QUAD
 #undef OGS_ENABLED_ELEMENTS
-
-#endif  // PROCESSLIB_SMALLDEFORMATION_LOCALDATAINITIALIZER_H_
diff --git a/ProcessLib/SmallDeformation/SmallDeformationFEM.h b/ProcessLib/SmallDeformation/SmallDeformationFEM.h
index 9f7df1474a33c867fdd0f837c64d713fff7a83e9..c2c2a02c9fa0eec3cadc0d515d78bb4f493165ef 100644
--- a/ProcessLib/SmallDeformation/SmallDeformationFEM.h
+++ b/ProcessLib/SmallDeformation/SmallDeformationFEM.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_SMALLDEFORMATION_FEM_H_
-#define PROCESS_LIB_SMALLDEFORMATION_FEM_H_
+#pragma once
 
 #include <memory>
 #include <vector>
@@ -440,5 +439,3 @@ public:
 
 }  // namespace SmallDeformation
 }  // namespace ProcessLib
-
-#endif  // PROCESS_LIB_SMALLDEFORMATION_FEM_H_
diff --git a/ProcessLib/SmallDeformation/SmallDeformationProcess-fwd.h b/ProcessLib/SmallDeformation/SmallDeformationProcess-fwd.h
index 8972b428a41a0846e84a6dfdf55f73382be95b1c..0022328eded4c434872ff36fcee2ccf955a03740 100644
--- a/ProcessLib/SmallDeformation/SmallDeformationProcess-fwd.h
+++ b/ProcessLib/SmallDeformation/SmallDeformationProcess-fwd.h
@@ -7,12 +7,9 @@
  *
  */
 
-#ifndef PROCESS_LIB_SMALLDEFORMATIONPROCESS_FWD_H_
-#define PROCESS_LIB_SMALLDEFORMATIONPROCESS_FWD_H_
+#pragma once
 
 #include "SmallDeformationProcess.h"
 
 extern template class ProcessLib::SmallDeformation::SmallDeformationProcess<2>;
 extern template class ProcessLib::SmallDeformation::SmallDeformationProcess<3>;
-
-#endif  // PROCESS_LIB_SMALLDEFORMATIONPROCESS_FWD_H_
diff --git a/ProcessLib/SmallDeformation/SmallDeformationProcess.h b/ProcessLib/SmallDeformation/SmallDeformationProcess.h
index dedff1753a90bd31430dc7a1984d0c628cd4d279..a5c92921db6d0767374268609ddcbd4d42b98557 100644
--- a/ProcessLib/SmallDeformation/SmallDeformationProcess.h
+++ b/ProcessLib/SmallDeformation/SmallDeformationProcess.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_SMALLDEFORMATIONPROCESS_H_
-#define PROCESS_LIB_SMALLDEFORMATIONPROCESS_H_
+#pragma once
 
 #include <cassert>
 
@@ -201,5 +200,3 @@ private:
 
 }  // namespace SmallDeformation
 }  // namespace ProcessLib
-
-#endif  // PROCESS_LIB_SMALLDEFORMATIONPROCESS_H_
diff --git a/ProcessLib/SmallDeformation/SmallDeformationProcessData.h b/ProcessLib/SmallDeformation/SmallDeformationProcessData.h
index 75e67513df391b52297008acbfc9db9af42c6ffd..9f6a5115f062c48bf5e51590138fccafbb772568 100644
--- a/ProcessLib/SmallDeformation/SmallDeformationProcessData.h
+++ b/ProcessLib/SmallDeformation/SmallDeformationProcessData.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_SMALLDEFORMATION_SMALLDEFORMATIONPROCESSDATA_H_
-#define PROCESSLIB_SMALLDEFORMATION_SMALLDEFORMATIONPROCESSDATA_H_
+#pragma once
 
 namespace MeshLib
 {
@@ -51,5 +50,3 @@ struct SmallDeformationProcessData
 
 }  // namespace SmallDeformation
 }  // namespace ProcessLib
-
-#endif  // PROCESSLIB_SMALLDEFORMATION_SMALLDEFORMATIONPROCESSDATA_H_
diff --git a/ProcessLib/TES/CreateTESProcess.h b/ProcessLib/TES/CreateTESProcess.h
index 1af2b064e4ce64145ee9b5d8730b4d2b763614c1..2c2d1bd42c136e101ef92c0019cb2becfb8425fc 100644
--- a/ProcessLib/TES/CreateTESProcess.h
+++ b/ProcessLib/TES/CreateTESProcess.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_CREATE_TESPROCESS_H_
-#define PROCESS_LIB_CREATE_TESPROCESS_H_
+#pragma once
 
 #include <memory>
 #include "ProcessLib/Process.h"
@@ -27,5 +26,3 @@ std::unique_ptr<Process> createTESProcess(
 
 }  // namespace TES
 }  // namespace ProcessLib
-
-#endif  // PROCESS_LIB_CREATE_TESPROCESS_H_
diff --git a/ProcessLib/TES/TESAssemblyParams.h b/ProcessLib/TES/TESAssemblyParams.h
index 28db0264334c8b6698bf5aa3bfe7edcd712ca9d4..473db2e200c7715b6e5eda6d468eb2f9d4f47210 100644
--- a/ProcessLib/TES/TESAssemblyParams.h
+++ b/ProcessLib/TES/TESAssemblyParams.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_TESPROCESS_NOTPL_H_
-#define PROCESS_LIB_TESPROCESS_NOTPL_H_
+#pragma once
 
 #include <Eigen/Eigen>
 #include <Eigen/Sparse>
@@ -81,5 +80,3 @@ struct AssemblyParams
 }  // namespace TES
 
 }  // namespace ProcessLib
-
-#endif  // PROCESS_LIB_TESPROCESS_NOTPL_H_
diff --git a/ProcessLib/TES/TESLocalAssembler-impl.h b/ProcessLib/TES/TESLocalAssembler-impl.h
index 04678c52a6a87fa0e2474796ac326bb7dbc26af5..72cfe4c725e63534474bcfbfd378f59d9e16a9b2 100644
--- a/ProcessLib/TES/TESLocalAssembler-impl.h
+++ b/ProcessLib/TES/TESLocalAssembler-impl.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef PROCESS_LIB_TES_FEM_IMPL_H_
-#define PROCESS_LIB_TES_FEM_IMPL_H_
+#pragma once
 
 #include "MaterialLib/Adsorption/Adsorption.h"
 #include "MathLib/LinAlg/Eigen/EigenMapTools.h"
@@ -276,5 +275,3 @@ bool TESLocalAssembler<
 
 }  // namespace TES
 }  // namespace ProcessLib
-
-#endif  // PROCESS_LIB_TES_FEM_IMPL_H_
diff --git a/ProcessLib/TES/TESLocalAssembler.h b/ProcessLib/TES/TESLocalAssembler.h
index e3b11df0c0f1fe3216e234ab6f779e28df48086b..2b00c3561373804ad811ab51b29b0b8206f0e46c 100644
--- a/ProcessLib/TES/TESLocalAssembler.h
+++ b/ProcessLib/TES/TESLocalAssembler.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_TES_FEM_H_
-#define PROCESS_LIB_TES_FEM_H_
+#pragma once
 
 #include <memory>
 #include <vector>
@@ -133,5 +132,3 @@ private:
 }  // namespace ProcessLib
 
 #include "TESLocalAssembler-impl.h"
-
-#endif  // PROCESS_LIB_TES_FEM_H_
diff --git a/ProcessLib/TES/TESLocalAssemblerData.h b/ProcessLib/TES/TESLocalAssemblerData.h
index 502b45cd20ae4b04b5444fbad6c3b6a29a02a5d5..23baf2a421e82a8f50956f1c2798878a7197486c 100644
--- a/ProcessLib/TES/TESLocalAssemblerData.h
+++ b/ProcessLib/TES/TESLocalAssemblerData.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_TES_TESLOCALASSEMBLERDATA_H
-#define PROCESSLIB_TES_TESLOCALASSEMBLERDATA_H
+#pragma once
 
 #include "TESAssemblyParams.h"
 
@@ -56,4 +55,3 @@ struct TESLocalAssemblerData
 };
 }
 }  // namespaces
-#endif  // PROCESSLIB_TES_TESLOCALASSEMBLERDATA_H
diff --git a/ProcessLib/TES/TESLocalAssemblerInner-fwd.h b/ProcessLib/TES/TESLocalAssemblerInner-fwd.h
index 7051dadfb3ec83dca51b719d284b02a06f0b72fd..1f32d85c71ba0ee765e85ff3771bc1d1bbadf0e7 100644
--- a/ProcessLib/TES/TESLocalAssemblerInner-fwd.h
+++ b/ProcessLib/TES/TESLocalAssemblerInner-fwd.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_TESFEM_DATA_FWD_H_
-#define PROCESS_LIB_TESFEM_DATA_FWD_H_
+#pragma once
 
 #include "TESLocalAssemblerInner.h"
 
@@ -29,5 +28,3 @@ static_assert(OGS_EIGEN_DYNAMIC_SHAPE_MATRICES_FLAG == 0,
 #endif
 }
 }
-
-#endif  // PROCESS_LIB_TESFEM_DATA_FWD_H_
diff --git a/ProcessLib/TES/TESLocalAssemblerInner-impl.h b/ProcessLib/TES/TESLocalAssemblerInner-impl.h
index 20d2c13aecd8fa057894769ee0a2578cf40f7c62..2c3ce11144634fd46418c7cbe1a131f11e128d0c 100644
--- a/ProcessLib/TES/TESLocalAssemblerInner-impl.h
+++ b/ProcessLib/TES/TESLocalAssemblerInner-impl.h
@@ -10,8 +10,7 @@
  * not all of OGS6 has to be recompiled every time a small change is done.
  */
 
-#ifndef PROCESS_LIB_TESFEM_DATA_IMPL_H_
-#define PROCESS_LIB_TESFEM_DATA_IMPL_H_
+#pragma once
 
 #include <cstdio>
 #include <iostream>
@@ -313,5 +312,3 @@ void TESLocalAssemblerInner<Traits>::preEachAssemble()
 }  // namespace TES
 
 }  // namespace ProcessLib
-
-#endif  // PROCESS_LIB_TESFEM_DATA_IMPL_H_
diff --git a/ProcessLib/TES/TESLocalAssemblerInner.h b/ProcessLib/TES/TESLocalAssemblerInner.h
index 3cdce8e84abbb170314fb0ebb4b6b30c9f0311b5..70c2c97fee036ca92c540a647baf86adedb312fa 100644
--- a/ProcessLib/TES/TESLocalAssemblerInner.h
+++ b/ProcessLib/TES/TESLocalAssemblerInner.h
@@ -10,8 +10,7 @@
  * not all of OGS6 has to be recompiled every time a small change is done.
  */
 
-#ifndef PROCESS_LIB_TES_FEM_NOTPL_H_
-#define PROCESS_LIB_TES_FEM_NOTPL_H_
+#pragma once
 
 #include "NumLib/Fem/ShapeMatrixPolicy.h"
 #include "ProcessLib/LocalAssemblerTraits.h"
@@ -73,5 +72,3 @@ private:
 }  // namespace ProcessLib
 
 #include "TESLocalAssemblerInner-impl.h"
-
-#endif  // PROCESS_LIB_TES_FEM_NOTPL_H_
diff --git a/ProcessLib/TES/TESOGS5MaterialModels.h b/ProcessLib/TES/TESOGS5MaterialModels.h
index 0bbcf23b7dcfb3bb21afdf03aa882f7e30f57a14..9b2ccd3920b6fde709189f1fcb6f3c9306361cd6 100644
--- a/ProcessLib/TES/TESOGS5MaterialModels.h
+++ b/ProcessLib/TES/TESOGS5MaterialModels.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef PROCESSLIB_TES_OGS5MATERIALMODELS
-#define PROCESSLIB_TES_OGS5MATERIALMODELS
+#pragma once
 
 #include "MaterialLib/PhysicalConstant.h"
 #include "TESAssemblyParams.h"
@@ -404,5 +403,3 @@ inline double fluid_heat_conductivity(const double p,
 
 }  // TES
 }  // ProcessLib
-
-#endif  // PROCESSLIB_TES_OGS5MATERIALMODELS
diff --git a/ProcessLib/TES/TESProcess.h b/ProcessLib/TES/TESProcess.h
index 0cc71f9648aa88b016fdbe10ef5bdf87d34be772..34073e1a02526ecbe46e2337ce7f248f7323a5b2 100644
--- a/ProcessLib/TES/TESProcess.h
+++ b/ProcessLib/TES/TESProcess.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_TESPROCESS_H_
-#define PROCESS_LIB_TESPROCESS_H_
+#pragma once
 
 #include "NumLib/DOF/LocalToGlobalIndexMap.h"
 #include "ProcessLib/Process.h"
@@ -92,5 +91,3 @@ private:
 }  // namespace TES
 
 }  // namespace ProcessLib
-
-#endif  // PROCESS_LIB_TESPROCESS_H_
diff --git a/ProcessLib/TES/TESReactionAdaptor.h b/ProcessLib/TES/TESReactionAdaptor.h
index b0a128aeb270b34b5f530a946596d3b223c9023d..aeca2bf219ec70b3e6e17721571562c8bec913a4 100644
--- a/ProcessLib/TES/TESReactionAdaptor.h
+++ b/ProcessLib/TES/TESReactionAdaptor.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_TES_TESREACTIONADAPTOR_H
-#define PROCESSLIB_TES_TESREACTIONADAPTOR_H
+#pragma once
 
 #include <memory>
 #include <vector>
@@ -130,4 +129,3 @@ private:
 
 }  // namespace TES
 }  // namespace ProcessLib
-#endif  // PROCESSLIB_TES_TESREACTIONADAPTOR_H
diff --git a/ProcessLib/TwoPhaseFlowWithPP/CreateTwoPhaseFlowWithPPProcess.h b/ProcessLib/TwoPhaseFlowWithPP/CreateTwoPhaseFlowWithPPProcess.h
index b525abe1187cdfab62e893961616d2c187be6522..9f46501de39786dc09a40d1926e12442bba8d267 100644
--- a/ProcessLib/TwoPhaseFlowWithPP/CreateTwoPhaseFlowWithPPProcess.h
+++ b/ProcessLib/TwoPhaseFlowWithPP/CreateTwoPhaseFlowWithPPProcess.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef OGS_CREATETWOPHASEFLOWWITHPPPROCESS_H
-#define OGS_CREATETWOPHASEFLOWWITHPPPROCESS_H
+#pragma once
 
 #include <memory>
 #include "ProcessLib/Process.h"
@@ -29,5 +28,3 @@ std::unique_ptr<Process> CreateTwoPhaseFlowWithPPProcess(
         curves);
 }  // end of namespace
 }  // end of namespace
-
-#endif /* CREATETWOPHASEFLOWWITHPPPROCESS_H */
diff --git a/ProcessLib/TwoPhaseFlowWithPP/TwoPhaseFlowWithPPLocalAssembler-impl.h b/ProcessLib/TwoPhaseFlowWithPP/TwoPhaseFlowWithPPLocalAssembler-impl.h
index e4a039bc167240b90e14dcfbbd9ee1f0fbe88802..939b664468849ceb2f7f4bd12c507fcbbc59ec11 100644
--- a/ProcessLib/TwoPhaseFlowWithPP/TwoPhaseFlowWithPPLocalAssembler-impl.h
+++ b/ProcessLib/TwoPhaseFlowWithPP/TwoPhaseFlowWithPPLocalAssembler-impl.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef OGS_TWOPHASEFLOWWITHPPLOCALASSEMBLER_IMPL_H
-#define OGS_TWOPHASEFLOWWITHPPLOCALASSEMBLER_IMPL_H
+#pragma once
 
 #include "TwoPhaseFlowWithPPLocalAssembler.h"
 
@@ -204,5 +203,3 @@ void TwoPhaseFlowWithPPLocalAssembler<
 
 }  // end of namespace
 }  // end of namespace
-
-#endif
diff --git a/ProcessLib/TwoPhaseFlowWithPP/TwoPhaseFlowWithPPLocalAssembler.h b/ProcessLib/TwoPhaseFlowWithPP/TwoPhaseFlowWithPPLocalAssembler.h
index 1cf5dbde2b5367648b33263c00a2dd18d1a1d869..8953d93c893eb71883b97c4dc87b0c689591d29c 100644
--- a/ProcessLib/TwoPhaseFlowWithPP/TwoPhaseFlowWithPPLocalAssembler.h
+++ b/ProcessLib/TwoPhaseFlowWithPP/TwoPhaseFlowWithPPLocalAssembler.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef OGS_TWOPHASEFLOWWITHPPLOCALASSEMBLER_H
-#define OGS_TWOPHASEFLOWWITHPPLOCALASSEMBLER_H
+#pragma once
 
 #include <vector>
 
@@ -136,5 +135,3 @@ private:
 }  // end of namespace
 
 #include "TwoPhaseFlowWithPPLocalAssembler-impl.h"
-
-#endif /* TWOPHASEFLOWWITHPPLOCALASSEMBLER_H */
diff --git a/ProcessLib/TwoPhaseFlowWithPP/TwoPhaseFlowWithPPProcess.h b/ProcessLib/TwoPhaseFlowWithPP/TwoPhaseFlowWithPPProcess.h
index c0b05004dfb5f1d1636428dba65fb04b54876996..ee012075e0eae94d7977e8240dca87239d7e118b 100644
--- a/ProcessLib/TwoPhaseFlowWithPP/TwoPhaseFlowWithPPProcess.h
+++ b/ProcessLib/TwoPhaseFlowWithPP/TwoPhaseFlowWithPPProcess.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef OGS_TWOPHASEFLOWWITHPPPROCESS_H
-#define OGS_TWOPHASEFLOWWITHPPPROCESS_H
+#pragma once
 
 #include "MaterialLib/TwoPhaseModels/TwoPhaseFlowWithPPMaterialProperties.h"
 #include "MathLib/InterpolationAlgorithms/PiecewiseLinearInterpolation.h"
@@ -75,5 +74,3 @@ private:
 
 }  // end of namespace
 }  // end of namespace
-
-#endif /* TWOPHASEFLOWWITHPPPROCESS_H */
diff --git a/ProcessLib/TwoPhaseFlowWithPP/TwoPhaseFlowWithPPProcessData.h b/ProcessLib/TwoPhaseFlowWithPP/TwoPhaseFlowWithPPProcessData.h
index 0556490f3a7454beb30ab2bf4b637d0e443f70a7..6da20a21694f2252fd2427e17b290ceef3a10a1b 100644
--- a/ProcessLib/TwoPhaseFlowWithPP/TwoPhaseFlowWithPPProcessData.h
+++ b/ProcessLib/TwoPhaseFlowWithPP/TwoPhaseFlowWithPPProcessData.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_TWOPHASEFLOWWITHPP_TWOPHASEFLOWWITHPPPROCESSDATA_H
-#define PROCESSLIB_TWOPHASEFLOWWITHPP_TWOPHASEFLOWWITHPPPROCESSDATA_H
+#pragma once
 
 namespace MeshLib
 {
@@ -83,5 +82,3 @@ struct TwoPhaseFlowWithPPProcessData
 
 }  // namespace TwoPhaseFlowWithPP
 }  // namespace ProcessLib
-
-#endif  // PROCESSLIB_TwoPhaseFlowWithPP_TwoPhaseFlowWithPPPROCESSDATA_H
diff --git a/ProcessLib/UncoupledProcessesTimeLoop.h b/ProcessLib/UncoupledProcessesTimeLoop.h
index 93985e61318602a221677ae3e6928c693cde9b11..3d6f74dde46d282100cb5f7436e42820350b6cc0 100644
--- a/ProcessLib/UncoupledProcessesTimeLoop.h
+++ b/ProcessLib/UncoupledProcessesTimeLoop.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_UNCOUPLED_PROCESSES_TIMELOOP
-#define PROCESSLIB_UNCOUPLED_PROCESSES_TIMELOOP
+#pragma once
 
 #include <memory>
 #include <logog/include/logog.hpp>
@@ -52,5 +51,3 @@ std::unique_ptr<UncoupledProcessesTimeLoop> createUncoupledProcessesTimeLoop(
         nonlinear_solvers);
 
 }  // namespace ProcessLib
-
-#endif  // PROCESSLIB_UNCOUPLED_PROCESSES_TIMELOOP
diff --git a/ProcessLib/Utils/CreateLocalAssemblers.h b/ProcessLib/Utils/CreateLocalAssemblers.h
index e37a8253946882372f703104586eb1936614e005..13bd2c7eeb7b9b111e8815fbc98901cc60b640d1 100644
--- a/ProcessLib/Utils/CreateLocalAssemblers.h
+++ b/ProcessLib/Utils/CreateLocalAssemblers.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef PROCESSLIB_UTILS_CREATE_LOCAL_ASSEMBLERS_H_
-#define PROCESSLIB_UTILS_CREATE_LOCAL_ASSEMBLERS_H_
+#pragma once
 
 #include <vector>
 
@@ -101,5 +100,3 @@ void createLocalAssemblers(
 }
 
 }  // ProcessLib
-
-#endif  // PROCESSLIB_UTILS_CREATE_LOCAL_ASSEMBLERS_H_
diff --git a/ProcessLib/Utils/InitShapeMatrices.h b/ProcessLib/Utils/InitShapeMatrices.h
index f72add26f2d88d443dbe91faa4fef185b19c0438..41243128125fee3484547c89c867d29b1aa877cc 100644
--- a/ProcessLib/Utils/InitShapeMatrices.h
+++ b/ProcessLib/Utils/InitShapeMatrices.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef PROCESSLIB_UTILS_INIT_SHAPE_MATRICES_H_
-#define PROCESSLIB_UTILS_INIT_SHAPE_MATRICES_H_
+#pragma once
 
 #include <vector>
 
@@ -58,6 +57,3 @@ double interpolateXCoordinate(
 }
 
 } // ProcessLib
-
-
-#endif // PROCESSLIB_UTILS_INIT_SHAPE_MATRICES_H_
diff --git a/ProcessLib/Utils/LocalDataInitializer.h b/ProcessLib/Utils/LocalDataInitializer.h
index 81dbc4b9a017590499163d39ea79904c80ddab8b..539b2eb09938e26089d321710f119de924ebe671 100644
--- a/ProcessLib/Utils/LocalDataInitializer.h
+++ b/ProcessLib/Utils/LocalDataInitializer.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESS_LIB_LOCALDATAINITIALIVER_H_
-#define PROCESS_LIB_LOCALDATAINITIALIVER_H_
+#pragma once
 
 #include <functional>
 #include <memory>
@@ -396,5 +395,3 @@ private:
 #undef ENABLED_ELEMENT_TYPE_TRI
 #undef ENABLED_ELEMENT_TYPE_QUAD
 #undef OGS_ENABLED_ELEMENTS
-
-#endif  // PROCESS_LIB_LOCALDATAINITIALIVER_H_
diff --git a/ProcessLib/Utils/ParseSecondaryVariables.h b/ProcessLib/Utils/ParseSecondaryVariables.h
index 6ffafa166f4cf38e31d64d42ba2e371a4bf33254..6268ed8c27d37a76cccaa95d888ad0d7444f4825 100644
--- a/ProcessLib/Utils/ParseSecondaryVariables.h
+++ b/ProcessLib/Utils/ParseSecondaryVariables.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_UTILS_PARSESECONDARYVARIABLES_H
-#define PROCESSLIB_UTILS_PARSESECONDARYVARIABLES_H
+#pragma once
 
 namespace BaseLib { class ConfigTree; }
 namespace ProcessLib { class SecondaryVariableCollection; }
@@ -22,5 +21,3 @@ void parseSecondaryVariables(
     NumLib::NamedFunctionCaller& named_function_caller);
 
 } // namespace ProcessLib
-
-#endif // PROCESSLIB_UTILS_PARSESECONDARYVARIABLES_H
diff --git a/ProcessLib/Utils/ProcessUtils.h b/ProcessLib/Utils/ProcessUtils.h
index 9590fd2f8b8d8adf37030a18882adb80c9f87eab..c7aa7de6f33d7830051bcf440be515029b46ca58 100644
--- a/ProcessLib/Utils/ProcessUtils.h
+++ b/ProcessLib/Utils/ProcessUtils.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_UTILS_PROCESSUTILS_H
-#define PROCESSLIB_UTILS_PROCESSUTILS_H
+#pragma once
 
 #include <vector>
 #include "BaseLib/ConfigTree.h"
@@ -121,5 +120,3 @@ Parameter<ParameterDataType>& findParameter(
     return findParameter<ParameterDataType>(name, parameters, num_components);
 }
 }  // ProcessLib
-
-#endif  // PROCESSLIB_UTILS_PROCESSUTILS_H
diff --git a/ProcessLib/VariableTransformation.h b/ProcessLib/VariableTransformation.h
index a1286d762c75760fb1202c2334f06c4146a21029..8c82fc497abf7b6d002365771d80a621490b4bd8 100644
--- a/ProcessLib/VariableTransformation.h
+++ b/ProcessLib/VariableTransformation.h
@@ -9,8 +9,7 @@
  * not all of OGS6 has to be recompiled every time a small change is done.
  */
 
-#ifndef PROCESSLIB_VARIABLETRANSFORMATION_H
-#define PROCESSLIB_VARIABLETRANSFORMATION_H
+#pragma once
 
 namespace ProcessLib
 {
@@ -84,4 +83,3 @@ private:
 typedef TrafoScale Trafo;
 
 }
-#endif // PROCESSLIB_VARIABLETRANSFORMATION_H
diff --git a/ProcessLib/VectorMatrixAssembler.h b/ProcessLib/VectorMatrixAssembler.h
index eaaadc1fbd8b93eb40530ef8ab53acefb293ecfd..a017a00ab0050b4420d898588e0bf3a2106ee72c 100644
--- a/ProcessLib/VectorMatrixAssembler.h
+++ b/ProcessLib/VectorMatrixAssembler.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef PROCESSLIB_VECTORMATRIXASSEMBLER_H_
-#define PROCESSLIB_VECTORMATRIXASSEMBLER_H_
+#pragma once
 
 #include <vector>
 #include "NumLib/NumericsConfig.h"
@@ -65,5 +64,3 @@ private:
 };
 
 }   // namespace ProcessLib
-
-#endif  // PROCESSLIB_VECTORMATRIXASSEMBLER_H_
diff --git a/Tests/GeoLib/AutoCheckGenerators.h b/Tests/GeoLib/AutoCheckGenerators.h
index 239859dec330daba03cce4845a161d801fcd55e4..28c799d09393e72b7cd5476f32e1217e63b9e6e2 100644
--- a/Tests/GeoLib/AutoCheckGenerators.h
+++ b/Tests/GeoLib/AutoCheckGenerators.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/LICENSE.txt
  */
 
-#ifndef TESTS_GEOLIB_AUTOCHECKGENERATORS_H_
-#define TESTS_GEOLIB_AUTOCHECKGENERATORS_H_
+#pragma once
 
 #include <cmath>
 #include <memory>
@@ -101,5 +100,3 @@ struct PairSegmentGeneratorXY
 };
 
 }  // namespace autocheck
-
-#endif  // TESTS_GEOLIB_AUTOCHECKGENERATORS_H_
diff --git a/Tests/InstanceCounter.h b/Tests/InstanceCounter.h
index 573587002b84be6aaefc116457879bbe8b0bc8a1..2556a4769775f20af46b8806c80c56ffe0927ed7 100644
--- a/Tests/InstanceCounter.h
+++ b/Tests/InstanceCounter.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef TESTS_INSTANCECOUNTER_H
-#define TESTS_INSTANCECOUNTER_H
+#pragma once
 
 template <class T>
 class InstanceCounter
@@ -71,5 +70,3 @@ int InstanceCounter<T>::_num_destroyed = 0;
     (num_move) = InstanceCounter<type>::getNumberOfMoves();             \
     (num_copy) = InstanceCounter<type>::getNumberOfCopies();            \
     (num_inst) = InstanceCounter<type>::getNumberOfInstances()
-
-#endif // TESTS_INSTANCECOUNTER_H
diff --git a/Tests/MathLib/AutoCheckTools.h b/Tests/MathLib/AutoCheckTools.h
index f82a59489be918f4612c2decc11be00a696e4aec..eed06985275c2f908c7f9604947dc7a709109dc3 100644
--- a/Tests/MathLib/AutoCheckTools.h
+++ b/Tests/MathLib/AutoCheckTools.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/LICENSE.txt
  */
 
-#ifndef TESTS_MATHLIB_AUTOCHECKTOOLS_H_
-#define TESTS_MATHLIB_AUTOCHECKTOOLS_H_
+#pragma once
 
 #include <Eigen/Dense>
 #include <autocheck/autocheck.hpp>
@@ -139,4 +138,3 @@ struct progressivelySmallerGenerator
 };
 
 }  // namespace autocheck
-#endif  // TESTS_MATHLIB_AUTOCHECKTOOLS_H_
diff --git a/Tests/NumLib/CoordinatesMappingTestData/TestHex8.h b/Tests/NumLib/CoordinatesMappingTestData/TestHex8.h
index ace84a91a0adf5a2050414d84ff5b67a7bfdd4a0..5072b65d4fb701d3587509fd22803910e2d79b61 100644
--- a/Tests/NumLib/CoordinatesMappingTestData/TestHex8.h
+++ b/Tests/NumLib/CoordinatesMappingTestData/TestHex8.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/LICENSE.txt
  */
 
-#ifndef COORDINATESMAPPINGTESTDATA_TESTHEX8_H_
-#define COORDINATESMAPPINGTESTDATA_TESTHEX8_H_
+#pragma once
 
 #include "MeshLib/Elements/Hex.h"
 #include "NumLib/Fem/ShapeFunction/ShapeHex8.h"
@@ -121,7 +120,3 @@ const double TestHex8::cl_exp_detJ = -1.;
 const double TestHex8::ze_exp_J[dim*dim] = {1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0};
 
 }
-
-#endif //OGS_USE_EIGEN
-
-
diff --git a/Tests/NumLib/CoordinatesMappingTestData/TestLine2.h b/Tests/NumLib/CoordinatesMappingTestData/TestLine2.h
index 9ddd9f159972f7e3d4cb799918fd477a3e4b87db..a9ec867d8eb455cac4fd6be3ed394d82be9ee7f8 100644
--- a/Tests/NumLib/CoordinatesMappingTestData/TestLine2.h
+++ b/Tests/NumLib/CoordinatesMappingTestData/TestLine2.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/LICENSE.txt
  */
 
-#ifndef COORDINATESMAPPINGTESTDATA_TESTLINE2_H_
-#define COORDINATESMAPPINGTESTDATA_TESTLINE2_H_
+#pragma once
 
 #include "MeshLib/Elements/Line.h"
 #include "NumLib/Fem/ShapeFunction/ShapeLine2.h"
@@ -99,5 +98,3 @@ const double TestLine2::cl_exp_detJ = -1;
 const double TestLine2::ze_exp_J[dim*dim] = {0.0};
 
 }
-
-#endif
diff --git a/Tests/NumLib/CoordinatesMappingTestData/TestLine3.h b/Tests/NumLib/CoordinatesMappingTestData/TestLine3.h
index 594cdceb64ad9306fe1412254cee4ce4fbc955b1..f15a1c8ce48d1604b86b4062e7492691c269823a 100644
--- a/Tests/NumLib/CoordinatesMappingTestData/TestLine3.h
+++ b/Tests/NumLib/CoordinatesMappingTestData/TestLine3.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/LICENSE.txt
  */
 
-#ifndef COORDINATESMAPPINGTESTDATA_TESTLINE3_H_
-#define COORDINATESMAPPINGTESTDATA_TESTLINE3_H_
+#pragma once
 
 #include "MeshLib/Elements/Line.h"
 #include "NumLib/Fem/ShapeFunction/ShapeLine3.h"
@@ -102,5 +101,3 @@ const double TestLine3::cl_exp_J[dim * dim] = {-1.};
 const double TestLine3::cl_exp_detJ = -1;
 const double TestLine3::ze_exp_J[dim * dim] = {0.0};
 }
-
-#endif
diff --git a/Tests/NumLib/CoordinatesMappingTestData/TestQuad4.h b/Tests/NumLib/CoordinatesMappingTestData/TestQuad4.h
index 654a15152fdc787eb9a7486490f4bc523a021e5f..2e66f0f8d7b0e03fb34c39abe8f7e90e04075e4f 100644
--- a/Tests/NumLib/CoordinatesMappingTestData/TestQuad4.h
+++ b/Tests/NumLib/CoordinatesMappingTestData/TestQuad4.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/LICENSE.txt
  */
 
-#ifndef COORDINATESMAPPINGTESTDATA_TESTQUAD4_H_
-#define COORDINATESMAPPINGTESTDATA_TESTQUAD4_H_
+#pragma once
 
 #include "MeshLib/Elements/Quad.h"
 #include "NumLib/Fem/ShapeFunction/ShapeQuad4.h"
@@ -101,6 +100,3 @@ const double TestQuad4::cl_exp_detJ = -1.;
 const double TestQuad4::ze_exp_J[dim*dim] = {1.0, 0.0, 0.0, 0.0};
 
 }
-
-#endif
-
diff --git a/Tests/NumLib/CoordinatesMappingTestData/TestTri3.h b/Tests/NumLib/CoordinatesMappingTestData/TestTri3.h
index 793b01e8c36d92c1f9078283c224e8649d6b7ec1..84269f1a474d11a301ed1b1aeea2c7aa77dd9817 100644
--- a/Tests/NumLib/CoordinatesMappingTestData/TestTri3.h
+++ b/Tests/NumLib/CoordinatesMappingTestData/TestTri3.h
@@ -6,8 +6,7 @@
  *              http://www.opengeosys.org/LICENSE.txt
  */
 
-#ifndef COORDINATESMAPPINGTESTDATA_TESTTRI3_H_
-#define COORDINATESMAPPINGTESTDATA_TESTTRI3_H_
+#pragma once
 
 #include "MeshLib/Elements/Tri.h"
 #include "NumLib/Fem/ShapeFunction/ShapeTri3.h"
@@ -96,5 +95,3 @@ const double TestTri3::cl_exp_detJ = -1.;
 const double TestTri3::ze_exp_J[dim*dim] = {1.0, 0.0, 1.0, 0.0};
 
 }
-
-#endif
diff --git a/Tests/NumLib/FeTestData/MatrixTools.h b/Tests/NumLib/FeTestData/MatrixTools.h
index a623ca68de432de14729a6192175606e6e815e74..ebe4e449dae0bb0a32bea4bc3efe3f690579cd2e 100644
--- a/Tests/NumLib/FeTestData/MatrixTools.h
+++ b/Tests/NumLib/FeTestData/MatrixTools.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef TEST_MATRIXTOOLS_H_
-#define TEST_MATRIXTOOLS_H_
+#pragma once
 
 namespace FeTestData
 {
@@ -34,6 +33,3 @@ inline void setIdentityMatrix(unsigned dim, T_MATRIX &m)
 }
 
 } // namespace
-
-#endif
-
diff --git a/Tests/NumLib/FeTestData/TestFeHEX8.h b/Tests/NumLib/FeTestData/TestFeHEX8.h
index 77af05feadffbd7586b2193dd482de6decad8705..1792de0bd46aa711e19bbbcf0bdb8f7b6b72df2b 100644
--- a/Tests/NumLib/FeTestData/TestFeHEX8.h
+++ b/Tests/NumLib/FeTestData/TestFeHEX8.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef TESTFEHEX8_H_
-#define TESTFEHEX8_H_
+#pragma once
 
 #include "MeshLib/Elements/Hex.h"
 #include "NumLib/Fem/FiniteElement/C0IsoparametricElements.h"
@@ -89,6 +88,3 @@ public:
 };
 
 } // namespace
-
-#endif
-
diff --git a/Tests/NumLib/FeTestData/TestFeLINE2.h b/Tests/NumLib/FeTestData/TestFeLINE2.h
index 7d5d806ae711b2e7969f8aa871a07e6d5b789937..b921646dcfaecb6a77777927a36ba78da178ae9b 100644
--- a/Tests/NumLib/FeTestData/TestFeLINE2.h
+++ b/Tests/NumLib/FeTestData/TestFeLINE2.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef TESTFELINE2_H_
-#define TESTFELINE2_H_
+#pragma once
 
 #include "MeshLib/Elements/Line.h"
 #include "NumLib/Fem/FiniteElement/C0IsoparametricElements.h"
@@ -69,6 +68,3 @@ public:
 };
 
 } // namespace
-
-#endif
-
diff --git a/Tests/NumLib/FeTestData/TestFeLINE2Y.h b/Tests/NumLib/FeTestData/TestFeLINE2Y.h
index 0971ad6d59da81008892f091b1c6328a2e59fdcc..31e7c8a2dcc8e9fec1a0d2bc8a60dc5ee3ade70c 100644
--- a/Tests/NumLib/FeTestData/TestFeLINE2Y.h
+++ b/Tests/NumLib/FeTestData/TestFeLINE2Y.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef TESTFELINE2Y_H_
-#define TESTFELINE2Y_H_
+#pragma once
 
 #include "MeshLib/Elements/Line.h"
 #include "NumLib/Fem/FiniteElement/C0IsoparametricElements.h"
@@ -68,6 +67,3 @@ public:
 };
 
 } // namespace
-
-#endif
-
diff --git a/Tests/NumLib/FeTestData/TestFeLINE3.h b/Tests/NumLib/FeTestData/TestFeLINE3.h
index 614c2478dc2dd734056b63e5772814b4702bcb61..7c396003c112f79aed09405932becf71428fa477 100644
--- a/Tests/NumLib/FeTestData/TestFeLINE3.h
+++ b/Tests/NumLib/FeTestData/TestFeLINE3.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef TESTFELINE3_H_
-#define TESTFELINE3_H_
+#pragma once
 
 #include "MeshLib/Elements/Line.h"
 #include "NumLib/Fem/FiniteElement/C0IsoparametricElements.h"
@@ -71,6 +70,3 @@ public:
 };
 
 } // namespace
-
-#endif
-
diff --git a/Tests/NumLib/FeTestData/TestFePRISM6.h b/Tests/NumLib/FeTestData/TestFePRISM6.h
index 6c5492a20b31474846cd7e04b2d2d0a0106a32d8..114ff74de3dd1e95ce1e94fac41be496b25f261d 100644
--- a/Tests/NumLib/FeTestData/TestFePRISM6.h
+++ b/Tests/NumLib/FeTestData/TestFePRISM6.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef TESTFEPRISM6_H_
-#define TESTFEPRISM6_H_
+#pragma once
 
 #include "MeshLib/Elements/Prism.h"
 #include "NumLib/Fem/FiniteElement/C0IsoparametricElements.h"
@@ -82,6 +81,3 @@ public:
 };
 
 } // namespace
-
-#endif
-
diff --git a/Tests/NumLib/FeTestData/TestFePYRA5.h b/Tests/NumLib/FeTestData/TestFePYRA5.h
index a759d7b1419e5c2f74e71d7720a2f3abe475c4f0..05c6b34b944684d99ece2e74adc35be3d7b23368 100644
--- a/Tests/NumLib/FeTestData/TestFePYRA5.h
+++ b/Tests/NumLib/FeTestData/TestFePYRA5.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef TESTFEPYRA5_H_
-#define TESTFEPYRA5_H_
+#pragma once
 
 #include "MeshLib/Elements/Pyramid.h"
 #include "NumLib/Fem/FiniteElement/C0IsoparametricElements.h"
@@ -78,6 +77,3 @@ public:
 };
 
 } // namespace
-
-#endif
-
diff --git a/Tests/NumLib/FeTestData/TestFeQUAD4.h b/Tests/NumLib/FeTestData/TestFeQUAD4.h
index aca8e53d163ffd35e7fac91999aaeeabe3a0f847..f67805edfe6536bb8f75afd214100bd916d59623 100644
--- a/Tests/NumLib/FeTestData/TestFeQUAD4.h
+++ b/Tests/NumLib/FeTestData/TestFeQUAD4.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef TESTFEQUAD4_H_
-#define TESTFEQUAD4_H_
+#pragma once
 
 #include "MeshLib/Elements/Quad.h"
 #include "NumLib/Fem/FiniteElement/C0IsoparametricElements.h"
@@ -77,6 +76,3 @@ public:
 };
 
 } // namespace
-
-#endif
-
diff --git a/Tests/NumLib/FeTestData/TestFeTET4.h b/Tests/NumLib/FeTestData/TestFeTET4.h
index b7c9266ba22aa1a44b66cfae728973cd58d9b86a..36a58ab0d6b383239e594f63a5ceae0a8641aa09 100644
--- a/Tests/NumLib/FeTestData/TestFeTET4.h
+++ b/Tests/NumLib/FeTestData/TestFeTET4.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef TESTFETET4_H_
-#define TESTFETET4_H_
+#pragma once
 
 #include "MeshLib/Elements/Tet.h"
 #include "NumLib/Fem/FiniteElement/C0IsoparametricElements.h"
@@ -75,6 +74,3 @@ public:
 };
 
 } // namespace
-
-#endif
-
diff --git a/Tests/NumLib/FeTestData/TestFeTRI3.h b/Tests/NumLib/FeTestData/TestFeTRI3.h
index 5eb1763d26228cc73dd35ea9109ae5f32fcc3c0d..c118ba23ea517fea838c5fcf5b479af4c3670477 100644
--- a/Tests/NumLib/FeTestData/TestFeTRI3.h
+++ b/Tests/NumLib/FeTestData/TestFeTRI3.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef TESTFETRI3_H_
-#define TESTFETRI3_H_
+#pragma once
 
 #include "MeshLib/Elements/Tri.h"
 #include "NumLib/Fem/FiniteElement/C0IsoparametricElements.h"
@@ -73,6 +72,3 @@ public:
 };
 
 } // namespace
-
-#endif
-
diff --git a/Tests/NumLib/ODEs.h b/Tests/NumLib/ODEs.h
index ac083d0cb944c6c577087c45d0a441de72ec2bc7..848b62cda93f2e290b1649be0a858f7402b0d795 100644
--- a/Tests/NumLib/ODEs.h
+++ b/Tests/NumLib/ODEs.h
@@ -7,8 +7,7 @@
  *
  */
 
-#ifndef TESTS_NUMLIB_ODES_H
-#define TESTS_NUMLIB_ODES_H
+#pragma once
 
 #include <boost/math/constants/constants.hpp>
 #include "MathLib/LinAlg/LinAlg.h"
@@ -300,5 +299,3 @@ const double ODETraits<ODE3>::t0 = 0.0;
 const double ODETraits<ODE3>::t_end =
     0.5 * boost::math::constants::pi<double>();
 // ODE 3 end //////////////////////////////////////////////////////
-
-#endif // TESTS_NUMLIB_ODES_H
diff --git a/Tests/NumLib/SteadyDiffusion2DExample1.h b/Tests/NumLib/SteadyDiffusion2DExample1.h
index 0c924b62e9a84d40420fe5ca5477f86b1b223b96..909e515e9f64e681d9f5682fb5a423576e053d4b 100644
--- a/Tests/NumLib/SteadyDiffusion2DExample1.h
+++ b/Tests/NumLib/SteadyDiffusion2DExample1.h
@@ -10,8 +10,7 @@
  *
  */
 
-#ifndef STEADYDIFFUSION2DEXAMPLE1_H_
-#define STEADYDIFFUSION2DEXAMPLE1_H_
+#pragma once
 
 #include <cmath>
 #include <vector>
@@ -149,6 +148,3 @@ template<typename IndexType>struct SteadyDiffusion2DExample1
     LocalMatrixType _localA;
     LocalVectorType _localRhs;
 };
-
-
-#endif //STEADYDIFFUSION2DEXAMPLE1_H_
diff --git a/Tests/NumLib/TimeSteppingTestingTools.h b/Tests/NumLib/TimeSteppingTestingTools.h
index b2fe2766f062d7cfd5663a4c1035ea0037e833b5..0922d246883df3aa5556ba540dd5a3fa77b5a535 100644
--- a/Tests/NumLib/TimeSteppingTestingTools.h
+++ b/Tests/NumLib/TimeSteppingTestingTools.h
@@ -9,8 +9,7 @@
  *              http://www.opengeosys.org/project/license
  */
 
-#ifndef TIMESTEPPINGTESTINGTOOLS_H_
-#define TIMESTEPPINGTESTINGTOOLS_H_
+#pragma once
 
 #include <logog/include/logog.hpp>
 
@@ -47,5 +46,3 @@ std::vector<double> timeStepping(T_TIME_STEPPING &algorithm, T* obj=nullptr)
     return vec_t;
 }
 } // namespace
-
-#endif // TIMESTEPPINGTESTINGTOOLS_H_
diff --git a/Tests/TestTools.h b/Tests/TestTools.h
index ee61d1060f255d111732166427d51bba15c3aa84..42a8e309c4a634b33e3612794c6ed94b77fe32eb 100644
--- a/Tests/TestTools.h
+++ b/Tests/TestTools.h
@@ -15,8 +15,7 @@
 #include <gtest/gtest.h>
 #include <boost/property_tree/ptree_fwd.hpp>
 
-#ifndef TESTTOOLS_H_
-#define TESTTOOLS_H_
+#pragma once
 
 #define ASSERT_ARRAY_NEAR(E,A,N,eps)\
     for (std::size_t i=0; i<(unsigned)(N); i++) \
@@ -28,5 +27,3 @@
 
 boost::property_tree::ptree
 readXml(const char xml[]);
-
-#endif // TESTTOOLS_H_