[PL] Reflection support for IP writers

ProcessLib/Reflection/ReflectionForIPWriters.h

+/**
+ * \file
+ * \copyright
+ * Copyright (c) 2012-2022, OpenGeoSys Community (http://www.opengeosys.org)
+ *            Distributed under a Modified BSD License.
+ *              See accompanying file LICENSE.txt or
+ *              http://www.opengeosys.org/project/license
+ *
+ */
+
+#pragma once
+
+#include "MeshLib/Utils/IntegrationPointWriter.h"
+#include "ReflectionIPData.h"
+
+namespace ProcessLib::Reflection
+{
+/// Adds IP data writers for all IP data obtained recursively from the given
+/// \c reflection_data to the given IP writer vector.
+template <int Dim, typename LocAsmIF, typename ReflData>
+void addReflectedIntegrationPointWriters(
+    ReflData const& reflection_data,
+    std::vector<std::unique_ptr<MeshLib::IntegrationPointWriter>>&
+        integration_point_writers,
+    unsigned const integration_order,
+    std::vector<std::unique_ptr<LocAsmIF>> const& local_assemblers)
+{
+    forEachReflectedFlattenedIPDataAccessor<Dim, LocAsmIF>(
+        reflection_data,
+        [&integration_point_writers, integration_order, &local_assemblers](
+            std::string const& name,
+            unsigned const num_comp,
+            auto&& flattened_ip_data_accessor)
+        {
+            // TODO check if writer with such a name already exists.
+            integration_point_writers.emplace_back(
+                std::make_unique<MeshLib::IntegrationPointWriter>(
+                    name + "_ip", num_comp, integration_order, local_assemblers,
+                    flattened_ip_data_accessor));
+        });
+}
+}  // namespace ProcessLib::Reflection