ADD: new track message, Entity class and Position class

libs/geographiclib/src/Accumulator.cpp

@@ -0,0 +1,21 @@
+/**
+ * \file Accumulator.cpp
+ * \brief Implementation for GeographicLib::Accumulator class
+ *
+ * Copyright (c) Charles Karney (2013-2022) <charles@karney.com> and licensed
+ * under the MIT/X11 License.  For more information, see
+ * https://geographiclib.sourceforge.io/
+ **********************************************************************/
+
+#include <GeographicLib/Accumulator.hpp>
+
+namespace GeographicLib {
+
+  /// \cond SKIP
+
+  // Need to instantiate Accumulator to get the code into the shared library.
+  template class GEOGRAPHICLIB_EXPORT Accumulator<Math::real>;
+
+  /// \endcond
+
+} // namespace GeographicLib