Don't include MPI cxx symbols properly

libsrc/core/CMakeLists.txt

@@ -93,7 +93,7 @@ install(FILES ngcore.hpp archive.hpp type_traits.hpp version.hpp ngcore_api.hpp
   xbool.hpp signal.hpp bitarray.hpp table.hpp hashtable.hpp ranges.hpp ngstream.hpp
   simd.hpp simd_avx.hpp simd_avx512.hpp simd_generic.hpp simd_sse.hpp simd_arm64.hpp
   register_archive.hpp autodiff.hpp autodiffdiff.hpp
-  ng_mpi.hpp ng_mpi_generated_declarations.hpp ng_mpi_native.hpp mpi4py_pycapi.h
+  ng_mpi.hpp ng_mpi_generated_declarations.hpp mpi4py_pycapi.h
   DESTINATION ${NG_INSTALL_DIR_INCLUDE}/core COMPONENT netgen_devel)
 
 if(ENABLE_CPP_CORE_GUIDELINES_CHECK)

libsrc/core/ng_mpi.cpp

@@ -1,9 +1,8 @@
 #define OMPI_SKIP_MPICXX
+#include <mpi.h>
 
 #include "ng_mpi.hpp"
 
-#include <mpi.h>
-
 #include <type_traits>
 
 #include "array.hpp"

libsrc/core/ng_mpi.hpp

@@ -10,6 +10,7 @@
 #include "ngcore_api.hpp"
 
 #ifndef NG_MPI_WRAPPER
+#define OMPI_SKIP_MPICXX
 #include <mpi.h>
 #endif  // NG_MPI_WRAPPER
 

libsrc/core/ng_mpi_native.hpp

@@ -1,21 +0,0 @@
-#ifndef NG_MPI_NATIVE_HPP
-#define NG_MPI_NATIVE_HPP
-
-#include <mpi.h>
-
-#include "mpi_wrapper.hpp"
-#include "ng_mpi.hpp"
-
-namespace ngcore {
-
-MPI_Comm NG_MPI_Native(NG_MPI_Comm comm) {
-  return reinterpret_cast<MPI_Comm>(comm.value);
-}
-
-MPI_Comm NG_MPI_Native(NgMPI_Comm comm) {
-  return reinterpret_cast<MPI_Comm>(static_cast<NG_MPI_Comm>(comm).value);
-}
-
-}  // namespace ngcore
-
-#endif  // NG_MPI_NATIVE_HPP

libsrc/core/ng_mpi_wrapper.cpp

@@ -14,7 +14,6 @@ using std::cout;
 using std::endl;
 
 #ifndef NG_MPI_WRAPPER
-#include <mpi.h>
 #define MPI4PY_LIMITED_API 1
 #define MPI4PY_LIMITED_API_SKIP_MESSAGE 1
 #define MPI4PY_LIMITED_API_SKIP_SESSION 1