stl_pair.h (pair<>::pair(_U1&&, const _T2&), [...]): Revert to…

stl_pair.h (pair<>::pair(_U1&&, const _T2&), [...]): Revert to std::is_convertible, basing on DR 811.

2010-02-07  Paolo Carlini  <paolo.carlini@oracle.com>

	* include/bits/stl_pair.h (pair<>::pair(_U1&&, const _T2&),
	pair<>::pair(const _T1&, _U2&&), pair<>::pair(_U1&&, _U2&&)):
	Revert to std::is_convertible, basing on DR 811.

From-SVN: r156570

libstdc++-v3/ChangeLog

+2010-02-07  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	* include/bits/stl_pair.h (pair<>::pair(_U1&&, const _T2&),
+	pair<>::pair(const _T1&, _U2&&), pair<>::pair(_U1&&, _U2&&)):
+	Revert to std::is_convertible, basing on DR 811.
+
 2010-02-06  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR libstdc++/42989

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

 // Pair implementation -*- C++ -*-
 
-// Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
+// Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
 // Free Software Foundation, Inc.
 //
 // This file is part of the GNU ISO C++ Library.  This library is free
@@ -90,20 +90,20 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
 #ifdef __GXX_EXPERIMENTAL_CXX0X__
       // DR 811.
       template<class _U1, class = typename
-	       std::enable_if<std::is_constructible<_T1, _U1&&>::value>::type>
+	       std::enable_if<std::is_convertible<_U1, _T1>::value>::type>
         pair(_U1&& __x, const _T2& __y)
 	: first(std::forward<_U1>(__x)),
 	  second(__y) { }
 
       template<class _U2, class = typename
-	       std::enable_if<std::is_constructible<_T2, _U2&&>::value>::type>
+	       std::enable_if<std::is_convertible<_U2, _T2>::value>::type>
         pair(const _T1& __x, _U2&& __y)
 	: first(__x),
 	  second(std::forward<_U2>(__y)) { }
 
       template<class _U1, class _U2, class = typename
-	       std::enable_if<std::is_constructible<_T1, _U1&&>::value
-			    && std::is_constructible<_T2, _U2&&>::value>::type>
+	       std::enable_if<std::is_convertible<_U1, _T1>::value
+			      && std::is_convertible<_U2, _T2>::value>::type>
         pair(_U1&& __x, _U2&& __y)
 	: first(std::forward<_U1>(__x)),
 	  second(std::forward<_U2>(__y)) { }