[patch] libstdc++/70294 Define std::thread::id comparison operators at namespace-scope

[Jonathan Wakely <jwakely at redhat dot com>]

The operator< and operator== for std::thread::id are not visible at
namespace scope, so can only be found by ADL. This fixes it.

Tested x86_64-linux, committed to trunk.


commit 8ca18880b4c6995fbccfb661eb652ebe9cd7f75f
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Mon Apr 18 16:58:13 2016 +0100

    Define std::thread::id comparison operators at namespace-scope

diff --git a/libstdc++-v3/include/std/thread b/libstdc++-v3/include/std/thread
index ad31fbc..15aa9a9 100644
--- a/libstdc++-v3/include/std/thread
+++ b/libstdc++-v3/include/std/thread
@@ -88,22 +88,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       friend class hash<thread::id>;
 
       friend bool
-      operator==(thread::id __x, thread::id __y) noexcept
-      {
-	// pthread_equal is undefined if either thread ID is not valid, so we
-	// can't safely use __gthread_equal on default-constructed values (nor
-	// the non-zero value returned by this_thread::get_id() for
-	// single-threaded programs using GNU libc). Assume EqualityComparable.
-	return __x._M_thread == __y._M_thread;
-      }
+      operator==(thread::id __x, thread::id __y) noexcept;
 
       friend bool
-      operator<(thread::id __x, thread::id __y) noexcept
-      {
-	// Pthreads doesn't define any way to do this, so we just have to
-	// assume native_handle_type is LessThanComparable.
-	return __x._M_thread < __y._M_thread;
-      }
+      operator<(thread::id __x, thread::id __y) noexcept;
 
       template<class _CharT, class _Traits>
 	friend basic_ostream<_CharT, _Traits>&
@@ -231,10 +219,28 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   { __x.swap(__y); }
 
   inline bool
+  operator==(thread::id __x, thread::id __y) noexcept
+  {
+    // pthread_equal is undefined if either thread ID is not valid, so we
+    // can't safely use __gthread_equal on default-constructed values (nor
+    // the non-zero value returned by this_thread::get_id() for
+    // single-threaded programs using GNU libc). Assume EqualityComparable.
+    return __x._M_thread == __y._M_thread;
+  }
+
+  inline bool
   operator!=(thread::id __x, thread::id __y) noexcept
   { return !(__x == __y); }
 
   inline bool
+  operator<(thread::id __x, thread::id __y) noexcept
+  {
+    // Pthreads doesn't define any way to do this, so we just have to
+    // assume native_handle_type is LessThanComparable.
+    return __x._M_thread < __y._M_thread;
+  }
+
+  inline bool
   operator<=(thread::id __x, thread::id __y) noexcept
   { return !(__y < __x); }
 
diff --git a/libstdc++-v3/testsuite/30_threads/thread/id/70294.cc b/libstdc++-v3/testsuite/30_threads/thread/id/70294.cc
new file mode 100644
index 0000000..9717637
--- /dev/null
+++ b/libstdc++-v3/testsuite/30_threads/thread/id/70294.cc
@@ -0,0 +1,24 @@
+// Copyright (C) 2016 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++11" }
+// { dg-do compile }
+
+#include <thread>
+
+bool (*lt)(std::thread::id, std::thread::id) = &std::operator<;
+bool (*eq)(std::thread::id, std::thread::id) = &std::operator==;