[v3] Remove wa for c++/49045 in std::swap

[Paolo Carlini]

Hi,

tested x86_64-linux, committed to mainline.

Paolo.

//////////////////////////

2011-08-28  Paolo Carlini  <paolo.carl...@oracle.com>

        * include/bits/move.h (swap(_Tp(&)[_Nm], _Tp(&)[_Nm])): Remove
        workaround for c++/49045.
        * include/bits/algorithmfwd.h: Likewise.

Index: include/bits/move.h
===================================================================
--- include/bits/move.h (revision 178146)
+++ include/bits/move.h (working copy)
@@ -152,21 +152,13 @@
       __b = _GLIBCXX_MOVE(__tmp);
     }
 
-#ifdef __GXX_EXPERIMENTAL_CXX0X__
-  // To work around c++/49045.
-  template<typename _Tp>
-    struct __is_nothrow_swappable
-    { static const bool value = noexcept(swap(std::declval<_Tp&>(),
-                                             std::declval<_Tp&>())); };
-#endif
-
   // _GLIBCXX_RESOLVE_LIB_DEFECTS
   // DR 809. std::swap should be overloaded for array types.
   template<typename _Tp, size_t _Nm>
     inline void
     swap(_Tp (&__a)[_Nm], _Tp (&__b)[_Nm])
 #ifdef __GXX_EXPERIMENTAL_CXX0X__
-    noexcept(__is_nothrow_swappable<_Tp>::value)
+    noexcept(noexcept(swap(*__a, *__b)))
 #endif
     {
       for (size_t __n = 0; __n < _Nm; ++__n)
Index: include/bits/algorithmfwd.h
===================================================================
--- include/bits/algorithmfwd.h (revision 178146)
+++ include/bits/algorithmfwd.h (working copy)
@@ -558,9 +558,9 @@
 
   template<typename _Tp, size_t _Nm>
     void
-    swap(_Tp (&)[_Nm], _Tp (&)[_Nm])
+    swap(_Tp (&__a)[_Nm], _Tp (&__b)[_Nm])
 #ifdef __GXX_EXPERIMENTAL_CXX0X__
-    noexcept(__is_nothrow_swappable<_Tp>::value)
+    noexcept(noexcept(swap(*__a, *__b)))
 #endif
     ;