cppcoreguidelines-pro-type-union-access

According to https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md using union for type-punning is undefined behaviour.
 Replace it with std::memcpy

src/Base/Interpreter.cpp

@@ -513,8 +513,7 @@ void InterpreterSingleton::addType(PyTypeObject* Type,PyObject* Module, const ch
     // This function is responsible for adding inherited slots from a type's base class.
     if (PyType_Ready(Type) < 0)
         return;
-    union PyType_Object pyType = {Type};
-    PyModule_AddObject(Module, Name, pyType.o);
+    PyModule_AddObject(Module, Name, Base::getTypeAsObject(Type));
 }
 
 void InterpreterSingleton::addPythonPath(const char* Path)

src/Base/PyObjectBase.h

@@ -47,6 +47,7 @@
 #endif
 #define slots
 #include <bitset>
+#include <cstring>
 
 #include "Exception.h"
 #ifndef PYCXX_PYTHON_2TO3
@@ -90,15 +91,6 @@
 #define PyMOD_INIT_FUNC(name) PyMODINIT_FUNC PyInit_##name(void)
 #define PyMOD_Return(name) return name
 
-/**
- * Union to convert from PyTypeObject to PyObject pointer.
- */
-union PyType_Object {
-    PyTypeObject *t;
-    PyObject *o;
-};
-
-
 
 /*------------------------------
  * Basic defines
@@ -122,6 +114,14 @@ inline void Assert(int expr, char *msg)         // C++ assert
     };
 }
 
+inline PyObject* getTypeAsObject(PyTypeObject* type) {
+    // See https://en.cppreference.com/w/cpp/string/byte/memcpy
+    // and https://en.cppreference.com/w/cpp/language/reinterpret_cast
+    PyObject* obj;
+    std::memcpy(&obj, &type, sizeof type);
+    return obj;
+}
+
 }
 
 /*------------------------------

src/Base/QuantityPyImp.cpp

@@ -595,8 +595,7 @@ Py::Object QuantityPy::getUnit() const
 
 void QuantityPy::setUnit(Py::Object arg)
 {
-    union PyType_Object pyType = {&(Base::UnitPy::Type)};
-    Py::Type UnitType(pyType.o);
+    Py::Type UnitType(Base::getTypeAsObject(&Base::UnitPy::Type));
     if(!arg.isType(UnitType))
         throw Py::AttributeError("Not yet implemented");
 

src/Base/VectorPyImp.cpp

@@ -96,8 +96,7 @@ PyObject*  VectorPy::__reduce__(PyObject *args)
 
     Py::Tuple tuple(2);
 
-    union PyType_Object pyType = {&VectorPy::Type};
-    Py::Object type(pyType.o);
+    Py::Object type(Base::getTypeAsObject(&Base::VectorPy::Type));
     tuple.setItem(0, type);
 
     Base::Vector3d v = this->value();