Index: libstdc++-v3/config/os/mingw32/os_defines.h
===================================================================
--- libstdc++-v3/config/os/mingw32/os_defines.h	(revision 129382)
+++ libstdc++-v3/config/os/mingw32/os_defines.h	(working copy)
@@ -45,6 +45,13 @@
 #undef NOMINMAX
 #define NOMINMAX 1
 
+// mingw32 local hack: Override  _GLIBCXX_USE_WCHAR_T for wstring
+#define _GLIBCXX_USE_WSTRING 1
+
+// mingw32 local hack: Cast long double to doubles to workaround
+// printf bug.
+#define _GLIBCXX_NO_LONG_DOUBLE_IO 0
+
 // See libstdc++/20806.
 #define _GLIBCXX_HAVE_DOS_BASED_FILESYSTEM 1
 
Index: libstdc++-v3/include/bits/char_traits.h
===================================================================
--- libstdc++-v3/include/bits/char_traits.h	(revision 129382)
+++ libstdc++-v3/include/bits/char_traits.h	(working copy)
@@ -295,7 +295,7 @@
   };
 
 
-#ifdef _GLIBCXX_USE_WCHAR_T
+#if defined (_GLIBCXX_USE_WCHAR_T) || defined (_GLIBCXX_USE_WSTRING)
   /// @brief  21.1.3.2  char_traits specializations
   template<>
     struct char_traits<wchar_t>
@@ -303,8 +303,10 @@
       typedef wchar_t           char_type;
       typedef wint_t            int_type;
       typedef streamoff         off_type;
+#if defined (_GLIBCXX_USE_WCHAR_T)
       typedef wstreampos        pos_type;
       typedef mbstate_t         state_type;
+#endif
 
       static void
       assign(char_type& __c1, const char_type& __c2)
Index: libstdc++-v3/include/bits/stringfwd.h
===================================================================
--- libstdc++-v3/include/bits/stringfwd.h	(revision 129382)
+++ libstdc++-v3/include/bits/stringfwd.h	(working copy)
@@ -59,7 +59,7 @@
 
   typedef basic_string<char>    string;
 
-#ifdef _GLIBCXX_USE_WCHAR_T
+#if defined (_GLIBCXX_USE_WCHAR_T) || defined (_GLIBCXX_USE_WSTRING)
   template<> struct char_traits<wchar_t>;
 
   typedef basic_string<wchar_t> wstring;
Index: libstdc++-v3/include/c_std/std_cwchar.h
===================================================================
--- libstdc++-v3/include/c_std/std_cwchar.h	(revision 129382)
+++ libstdc++-v3/include/c_std/std_cwchar.h	(working copy)
@@ -138,7 +138,7 @@
 #undef wprintf
 #undef wscanf
 
-#if _GLIBCXX_USE_WCHAR_T
+#if _GLIBCXX_USE_WCHAR_T || _GLIBCXX_USE_WSTRING
 namespace std
 {
   using ::wint_t;
Index: libstdc++-v3/include/c_std/std_cwctype.h
===================================================================
--- libstdc++-v3/include/c_std/std_cwctype.h	(revision 129382)
+++ libstdc++-v3/include/c_std/std_cwctype.h	(working copy)
@@ -75,7 +75,7 @@
 #undef wctrans
 #undef wctype
 
-#if _GLIBCXX_USE_WCHAR_T
+#if _GLIBCXX_USE_WCHAR_T || _GLIBCXX_USE_WSTRING
 namespace std
 {
   using ::wint_t;	  // cwchar