[Time] Added a class for a time interval

NumLib/TimeStepping/TimeInterval.h

+/**
+ *
+ * \copyright
+ * Copyright (c) 2012-2018, OpenGeoSys Community (http://www.opengeosys.org)
+ *            Distributed under a Modified BSD License.
+ *              See accompanying file LICENSE.txt or
+ *              http://www.opengeosys.org/project/license
+ *
+ * File:   TimeInterval.h
+ *
+ * Created on November 26, 2018, 4:44 PM
+ */
+#pragma once
+
+namespace NumLib
+{
+/*!
+ * Class for a time interval, which has a member to check whether the given time
+ * is in this time interval.
+ */
+class TimeInterval
+{
+public:
+    TimeInterval(const double start_time, const double end_time)
+        : _start_time(start_time), _end_time(end_time)
+    {
+    }
+
+    bool isInThisTimeInterval(const double current_time) const
+    {
+        return (current_time >= _start_time && current_time <= _end_time)
+                   ? true
+                   : false;
+    }
+
+private:
+    const double _start_time;
+    const double _end_time;
+};
+
+}  // end of namespace