[Bug libstdc++/67114] [MinGW64] build failure with POSIX threads enabled

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67114

--- Comment #15 from Jonathan Wakely <redi at gcc dot gnu.org> ---
--- gcc-5.3.0.old/libstdc++-v3/include/std/thread       2015-03-26
20:59:08.000000000 +0100
+++ gcc-5.3.0.old/libstdc++-v3/include/std/thread       2016-03-17
06:32:41.124378000 +0100
@@ -83,10 +83,19 @@ 
       operator==(thread::id __x, thread::id __y) noexcept
       { return __gthread_equal(__x._M_thread, __y._M_thread); }

+      // implement operator< explicitly in terms of the internals of
+      // pthreads-win32's ptw32_handle_t so that std::thread can use pthreads
+#ifdef PTW32_VERSION
+      friend bool
+      operator<(thread::id __x, thread::id __y)
+      { return ( (__x._M_thread.p < __y._M_thread.p) || 
+         ((__x._M_thread.p == __y._M_thread.p) && (__x._M_thread.x <
__y._M_thread.x) ) ); }

I suggest:

 return std::tie(__x._M_thread.p, __x._M_thread.x)
      < std::tie(__y._M_thread.p, __y._M_thread.x);

+#else
       friend bool
       operator<(thread::id __x, thread::id __y) noexcept
-      { return __x._M_thread < __y._M_thread; }
-
+      {        return __less<native_handle_type>::_S_less(__x._M_thread,
__y._M_thread); }
+#endif
+  

What's this?