re PR libstdc++/38466 (Document std::pair vs. std::swap)

2009-01-07  Paolo Carlini  <paolo.carlini@oracle.com>

	PR libstdc++/38466
	* include/bits/stl_pair.h: Document C++03 pair vs swap.

From-SVN: r143154

libstdc++-v3/ChangeLog

+2009-01-07  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR libstdc++/38466
+	* include/bits/stl_pair.h: Document C++03 pair vs swap.
+
 2009-01-06  Benjamin Kosnik  <bkoz@redhat.com>
 
 	* src/locale_init.cc (locale::_S_initialize_once): Move construction

libstdc++-v3/include/bits/stl_pair.h

 // Pair implementation -*- C++ -*-
 
-// Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
+// Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
 // Free Software Foundation, Inc.
 //
 // This file is part of the GNU ISO C++ Library.  This library is free
@@ -184,6 +184,8 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
 
 #ifdef __GXX_EXPERIMENTAL_CXX0X__
   /// See std::pair::swap().
+  // Note:  no std::swap overloads in C++03 mode, this has performance
+  //        implications, see, eg, libstdc++/38466.
   template<class _T1, class _T2>
     inline void
     swap(pair<_T1, _T2>& __x, pair<_T1, _T2>& __y)