Fixes #48 ("MSVC warning C4643: Forward declaring 'nothrow_t' in namespace std is not permitted by the C++ Standard")

doc/move.qbk

@@ -802,6 +802,13 @@ Special thanks to:
 
 [section:release_notes Release Notes]
 
+[section:release_notes_boost_1_79 Boost 1.79 Release]
+
+*  Fixed bugs:
+   *  [@https://github.com/boostorg/move/issues/48 Git Issue #48: ['"MSVC warning C4643: Forward declaring 'nothrow_t' in namespace std is not permitted by the C++ Standard"]].
+
+[endsect]
+
 [section:release_notes_boost_1_78 Boost 1.78 Release]
 
 *  Fixed bugs:

include/boost/move/detail/std_ns_begin.hpp

@@ -24,7 +24,11 @@
    #define BOOST_MOVE_STD_NS_BEG _GLIBCXX_BEGIN_NAMESPACE(std)
    #define BOOST_MOVE_STD_NS_END _GLIBCXX_END_NAMESPACE
 #else
+   #if defined(_MSC_VER) && (_MSC_VER >= 1915)
+      #pragma warning (push)
+      #pragma warning (disable : 4643) // Forward declaring 'X' in namespace std is not permitted by the C++ Standard
+   #endif
+
    #define BOOST_MOVE_STD_NS_BEG namespace std{
    #define BOOST_MOVE_STD_NS_END }
 #endif
-

include/boost/move/detail/std_ns_end.hpp

@@ -11,4 +11,6 @@
 #ifdef BOOST_MOVE_STD_NS_GCC_DIAGNOSTIC_PUSH
    #pragma GCC diagnostic pop
    #undef BOOST_MOVE_STD_NS_GCC_DIAGNOSTIC_PUSH
+#elif defined(_MSC_VER) && (_MSC_VER >= 1915)
+   #pragma warning (pop)
 #endif   //BOOST_MOVE_STD_NS_GCC_DIAGNOSTIC_PUSH

include/boost/move/make_unique.hpp

@@ -38,12 +38,22 @@
  
 #if !defined(BOOST_MOVE_DOXYGEN_INVOKED)
 
+#if defined(_MSC_VER) && (_MSC_VER >= 1915)
+   #pragma warning (push)
+   #pragma warning (disable : 4643) // Forward declaring 'X' in namespace std is not permitted by the C++ Standard
+#endif
+
 namespace std {   //no namespace versioning in clang+libc++
 
 struct nothrow_t;
 
 }  //namespace std {
 
+#if defined(_MSC_VER) && (_MSC_VER >= 1915)
+   #pragma warning (pop)
+#endif
+
+
 namespace boost{
 namespace move_upmu {