X-Git-Url: http://git.sourceforge.jp/view?a=blobdiff_plain;f=libstdc%2B%2B-v3%2Finclude%2Fstd%2Ftuple;h=474634fc24e8b6b33ae650a85f1950d148b21ac4;hb=2b6ed700ac98f9851deaa6abac003d469920a334;hp=a0e9e694dc2bb586dfffecd5aee68373b75e88c2;hpb=82d002412200dec81a72d2cb2354539d407aa715;p=pf3gnuchains%2Fgcc-fork.git

diff --git a/libstdc++-v3/include/std/tuple b/libstdc++-v3/include/std/tuple
index a0e9e694dc2..474634fc24e 100644
--- a/libstdc++-v3/include/std/tuple
+++ b/libstdc++-v3/include/std/tuple
@@ -69,6 +69,35 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     struct __add_r_ref<_Tp&>
     { typedef _Tp& type; };
 
+  // To work around c++/49225 aka c++/48322.
+  template<typename...>
+    struct __conv_types { };
+
+  template<typename _Tuple1, typename _Tuple2>
+    struct __one_by_one_convertible
+    : public false_type { };
+
+  template<typename _Tp, typename _Up>
+    struct __one_by_one_convertible<__conv_types<_Tp>, __conv_types<_Up>>
+    : public is_convertible<_Tp, _Up>::type { };
+
+  template<typename _T1, typename... _TR, typename _U1, typename... _UR>
+    struct __one_by_one_convertible<__conv_types<_T1, _TR...>,
+                                    __conv_types<_U1, _UR...>>
+    : public __and_<is_convertible<_T1, _U1>,
+                    __one_by_one_convertible<__conv_types<_TR...>,
+                                             __conv_types<_UR...>>>::type
+    { };
+
+  template<typename _Tuple1, typename _Tuple2>
+    struct __all_convertible;
+
+  template<typename... _TTypes, typename... _UTypes>
+    struct __all_convertible<__conv_types<_TTypes...>,
+                             __conv_types<_UTypes...>>
+    : public __one_by_one_convertible<__conv_types<_TTypes...>,
+                                      __conv_types<_UTypes...>>::type { };
+
   template<std::size_t _Idx, typename _Head, bool _IsEmpty>
     struct _Head_base;
 
@@ -85,7 +114,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       template<typename _UHead, typename = typename
 	       enable_if<!is_convertible<_UHead,
 	                                 __uses_alloc_base>::value>::type>
-        _Head_base(_UHead&& __h)
+        constexpr _Head_base(_UHead&& __h)
 	: _Head(std::forward<_UHead>(__h)) { }
 
       _Head_base(__uses_alloc0)
@@ -111,8 +140,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	_Head_base(__uses_alloc2<_Alloc> __a, _UHead&& __uhead)
 	: _Head(std::forward<_UHead>(__uhead), *__a._M_a) { }
 
-      _Head&       _M_head() noexcept       { return *this; }
-      const _Head& _M_head() const noexcept { return *this; }
+      static constexpr _Head&
+      _M_head(_Head_base& __b) noexcept { return __b; }
+
+      static constexpr const _Head&
+      _M_head(const _Head_base& __b) noexcept { return __b; }
     };
 
   template<std::size_t _Idx, typename _Head>
@@ -127,7 +159,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       template<typename _UHead, typename = typename
 	       enable_if<!is_convertible<_UHead,
 	                                 __uses_alloc_base>::value>::type>
-        _Head_base(_UHead&& __h)
+        constexpr _Head_base(_UHead&& __h)
 	: _M_head_impl(std::forward<_UHead>(__h)) { }
 
       _Head_base(__uses_alloc0)
@@ -154,10 +186,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	_Head_base(__uses_alloc2<_Alloc> __a, _UHead&& __uhead)
 	: _M_head_impl(std::forward<_UHead>(__uhead), *__a._M_a) { }
 
-      _Head&       _M_head() noexcept       { return _M_head_impl; }
-      const _Head& _M_head() const noexcept { return _M_head_impl; }        
+      static constexpr _Head&
+      _M_head(_Head_base& __b) noexcept { return __b._M_head_impl; }
+
+      static constexpr const _Head&
+      _M_head(const _Head_base& __b) noexcept { return __b._M_head_impl; }
 
-      _Head _M_head_impl; 
+      _Head _M_head_impl;
     };
 
   /**
@@ -210,11 +245,17 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       typedef _Tuple_impl<_Idx + 1, _Tail...> _Inherited;
       typedef _Head_base<_Idx, _Head, std::is_empty<_Head>::value> _Base;
 
-      _Head&            _M_head() noexcept       { return _Base::_M_head(); }
-      const _Head&      _M_head() const noexcept { return _Base::_M_head(); }
+      static constexpr _Head&  
+      _M_head(_Tuple_impl& __t) noexcept { return _Base::_M_head(__t); }
 
-      _Inherited&       _M_tail() noexcept       { return *this; }
-      const _Inherited& _M_tail() const noexcept { return *this; }
+      static constexpr const _Head&
+      _M_head(const _Tuple_impl& __t) noexcept { return _Base::_M_head(__t); }
+
+      static constexpr _Inherited&
+      _M_tail(_Tuple_impl& __t) noexcept { return __t; }
+
+      static constexpr const _Inherited&
+      _M_tail(const _Tuple_impl& __t) noexcept { return __t; }
 
       constexpr _Tuple_impl()
       : _Inherited(), _Base() { }
@@ -224,28 +265,32 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       : _Inherited(__tail...), _Base(__head) { }
 
       template<typename _UHead, typename... _UTail, typename = typename
-               std::enable_if<sizeof...(_Tail)==sizeof...(_UTail)>::type> 
+               enable_if<sizeof...(_Tail) == sizeof...(_UTail)>::type> 
         explicit
-        _Tuple_impl(_UHead&& __head, _UTail&&... __tail)
+        constexpr _Tuple_impl(_UHead&& __head, _UTail&&... __tail)
 	: _Inherited(std::forward<_UTail>(__tail)...),
 	  _Base(std::forward<_UHead>(__head)) { }
 
       constexpr _Tuple_impl(const _Tuple_impl&) = default;
 
+      constexpr
       _Tuple_impl(_Tuple_impl&& __in)
-      noexcept(std::is_nothrow_move_constructible<_Head>::value
-	       && std::is_nothrow_move_constructible<_Inherited>::value)
-      : _Inherited(std::move(__in._M_tail())), 
-	_Base(std::forward<_Head>(__in._M_head())) { }
+      noexcept(__and_<is_nothrow_move_constructible<_Head>,
+	              is_nothrow_move_constructible<_Inherited>>::value)
+      : _Inherited(std::move(_M_tail(__in))), 
+	_Base(std::forward<_Head>(_M_head(__in))) { }
 
       template<typename... _UElements>
-        _Tuple_impl(const _Tuple_impl<_Idx, _UElements...>& __in)
-	: _Inherited(__in._M_tail()), _Base(__in._M_head()) { }
+        constexpr _Tuple_impl(const _Tuple_impl<_Idx, _UElements...>& __in)
+	: _Inherited(_Tuple_impl<_Idx, _UElements...>::_M_tail(__in)),
+	  _Base(_Tuple_impl<_Idx, _UElements...>::_M_head(__in)) { }
 
       template<typename _UHead, typename... _UTails>
-        _Tuple_impl(_Tuple_impl<_Idx, _UHead, _UTails...>&& __in)
-	: _Inherited(std::move(__in._M_tail())),
-	  _Base(std::forward<_UHead>(__in._M_head())) { }
+        constexpr _Tuple_impl(_Tuple_impl<_Idx, _UHead, _UTails...>&& __in)
+	: _Inherited(std::move
+		     (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_tail(__in))),
+	  _Base(std::forward<_UHead>
+		(_Tuple_impl<_Idx, _UHead, _UTails...>::_M_head(__in))) { }
 
       template<typename _Alloc>
 	_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a)
@@ -254,13 +299,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
       template<typename _Alloc>
 	_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
-	    const _Head& __head, const _Tail&... __tail)
+		    const _Head& __head, const _Tail&... __tail)
 	: _Inherited(__tag, __a, __tail...),
           _Base(__use_alloc<_Head, _Alloc, _Head>(__a), __head) { }
 
       template<typename _Alloc, typename _UHead, typename... _UTail,
-               typename = typename std::enable_if<sizeof...(_Tail)
-		                                  ==sizeof...(_UTail)>::type>
+               typename = typename enable_if<sizeof...(_Tail)
+					     == sizeof...(_UTail)>::type>
 	_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
 	            _UHead&& __head, _UTail&&... __tail)
 	: _Inherited(__tag, __a, std::forward<_UTail>(__tail)...),
@@ -270,46 +315,48 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       template<typename _Alloc>
         _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
 	            const _Tuple_impl& __in)
-	: _Inherited(__tag, __a, __in._M_tail()), 
-          _Base(__use_alloc<_Head, _Alloc, _Head>(__a), __in._M_head()) { }
+	: _Inherited(__tag, __a, _M_tail(__in)), 
+          _Base(__use_alloc<_Head, _Alloc, _Head>(__a), _M_head(__in)) { }
 
       template<typename _Alloc>
 	_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
 	            _Tuple_impl&& __in)
-	noexcept(std::is_nothrow_move_constructible<_Head>::value
-		 && std::is_nothrow_move_constructible<_Inherited>::value)
-	: _Inherited(__tag, __a, std::move(__in._M_tail())), 
+	: _Inherited(__tag, __a, std::move(_M_tail(__in))), 
 	  _Base(__use_alloc<_Head, _Alloc, _Head>(__a),
-	        std::forward<_Head>(__in._M_head())) { }
+	        std::forward<_Head>(_M_head(__in))) { }
 
       template<typename _Alloc, typename... _UElements>
 	_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
 	            const _Tuple_impl<_Idx, _UElements...>& __in)
-	: _Inherited(__tag, __a, __in._M_tail()),
-	  _Base(__use_alloc<_Head, _Alloc, _Head>(__a), __in._M_head()) { }
+	: _Inherited(__tag, __a,
+		     _Tuple_impl<_Idx, _UElements...>::_M_tail(__in)),
+	  _Base(__use_alloc<_Head, _Alloc, _Head>(__a),
+		_Tuple_impl<_Idx, _UElements...>::_M_head(__in)) { }
 
       template<typename _Alloc, typename _UHead, typename... _UTails>
 	_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
 	            _Tuple_impl<_Idx, _UHead, _UTails...>&& __in)
-	: _Inherited(__tag, __a, std::move(__in._M_tail())),
+	: _Inherited(__tag, __a, std::move
+		     (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_tail(__in))),
 	  _Base(__use_alloc<_Head, _Alloc, _UHead>(__a),
-                std::forward<_UHead>(__in._M_head())) { }
+                std::forward<_UHead>
+		(_Tuple_impl<_Idx, _UHead, _UTails...>::_M_head(__in))) { }
 
       _Tuple_impl&
       operator=(const _Tuple_impl& __in)
       {
-	_M_head() = __in._M_head();
-	_M_tail() = __in._M_tail();
+	_M_head(*this) = _M_head(__in);
+	_M_tail(*this) = _M_tail(__in);
 	return *this;
       }
 
       _Tuple_impl&
       operator=(_Tuple_impl&& __in)
-      noexcept(std::is_nothrow_move_assignable<_Head>::value
-	       && std::is_nothrow_move_assignable<_Inherited>::value)
+      noexcept(__and_<is_nothrow_move_assignable<_Head>,
+	              is_nothrow_move_assignable<_Inherited>>::value)
       {
-	_M_head() = std::forward<_Head>(__in._M_head());
-	_M_tail() = std::move(__in._M_tail());
+	_M_head(*this) = std::forward<_Head>(_M_head(__in));
+	_M_tail(*this) = std::move(_M_tail(__in));
 	return *this;
       }
 
@@ -317,8 +364,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
         _Tuple_impl&
         operator=(const _Tuple_impl<_Idx, _UElements...>& __in)
         {
-	  _M_head() = __in._M_head();
-	  _M_tail() = __in._M_tail();
+	  _M_head(*this) = _Tuple_impl<_Idx, _UElements...>::_M_head(__in);
+	  _M_tail(*this) = _Tuple_impl<_Idx, _UElements...>::_M_tail(__in);
 	  return *this;
 	}
 
@@ -326,8 +373,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
         _Tuple_impl&
         operator=(_Tuple_impl<_Idx, _UHead, _UTails...>&& __in)
         {
-	  _M_head() = std::forward<_UHead>(__in._M_head());
-	  _M_tail() = std::move(__in._M_tail());
+	  _M_head(*this) = std::forward<_UHead>
+	    (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_head(__in));
+	  _M_tail(*this) = std::move
+	    (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_tail(__in));
 	  return *this;
 	}
 
@@ -336,15 +385,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       _M_swap(_Tuple_impl& __in)
       noexcept(noexcept(swap(std::declval<_Head&>(),
 			     std::declval<_Head&>()))
-	       && noexcept(__in._M_tail()._M_swap(__in._M_tail())))
+	       && noexcept(_M_tail(__in)._M_swap(_M_tail(__in))))
       {
 	using std::swap;
-	swap(this->_M_head(), __in._M_head());
-	_Inherited::_M_swap(__in._M_tail());
+	swap(_M_head(*this), _M_head(__in));
+	_Inherited::_M_swap(_M_tail(__in));
       }
     };
 
-  /// tuple
+  /// Primary class template, tuple
   template<typename... _Elements> 
     class tuple : public _Tuple_impl<0, _Elements...>
     {
@@ -358,30 +407,41 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       constexpr tuple(const _Elements&... __elements)
       : _Inherited(__elements...) { }
 
-      template<typename... _UElements, typename = typename
-	       std::enable_if<sizeof...(_UElements)
-			      == sizeof...(_Elements)>::type>
-        explicit
-        tuple(_UElements&&... __elements)
+      template<typename... _UElements,
+	       typename = typename enable_if<sizeof...(_UElements)
+					     == sizeof...(_Elements)>::type,
+	       typename = typename
+	         enable_if<__all_convertible<__conv_types<_UElements...>,
+					     __conv_types<_Elements...> >::value
+			   >::type>
+	explicit
+        constexpr tuple(_UElements&&... __elements)
 	: _Inherited(std::forward<_UElements>(__elements)...) {	}
 
       constexpr tuple(const tuple&) = default;
-      tuple(tuple&&) = default;
+
+      constexpr tuple(tuple&&) = default; 
 
       template<typename... _UElements, typename = typename
-	       std::enable_if<sizeof...(_UElements)
-			      == sizeof...(_Elements)>::type>
-        tuple(const tuple<_UElements...>& __in)
+	enable_if<__and_<integral_constant<bool, sizeof...(_UElements)
+					   == sizeof...(_Elements)>,
+			 __all_convertible<__conv_types<const _UElements&...>,
+					   __conv_types<_Elements...>>
+                         >::value>::type>
+        constexpr tuple(const tuple<_UElements...>& __in)
         : _Inherited(static_cast<const _Tuple_impl<0, _UElements...>&>(__in))
         { }
 
       template<typename... _UElements, typename = typename
-	       std::enable_if<sizeof...(_UElements)
-			      == sizeof...(_Elements)>::type>
-        tuple(tuple<_UElements...>&& __in)
+	enable_if<__and_<integral_constant<bool, sizeof...(_UElements)
+					   == sizeof...(_Elements)>,
+			 __all_convertible<__conv_types<_UElements...>,
+					   __conv_types<_Elements...>>
+			 >::value>::type>
+        constexpr tuple(tuple<_UElements...>&& __in)
         : _Inherited(static_cast<_Tuple_impl<0, _UElements...>&&>(__in)) { }
 
-      // allocator-extended constructors
+      // Allocator-extended constructors.
 
       template<typename _Alloc>
 	tuple(allocator_arg_t __tag, const _Alloc& __a)
@@ -393,8 +453,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	: _Inherited(__tag, __a, __elements...) { }
 
       template<typename _Alloc, typename... _UElements, typename = typename
-	       std::enable_if<sizeof...(_UElements)
-			      == sizeof...(_Elements)>::type>
+	       enable_if<sizeof...(_UElements)
+			 == sizeof...(_Elements)>::type>
 	tuple(allocator_arg_t __tag, const _Alloc& __a,
 	      _UElements&&... __elements)
 	: _Inherited(__tag, __a, std::forward<_UElements>(__elements)...)
@@ -409,8 +469,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	: _Inherited(__tag, __a, static_cast<_Inherited&&>(__in)) { }
 
       template<typename _Alloc, typename... _UElements, typename = typename
-	       std::enable_if<sizeof...(_UElements)
-			      == sizeof...(_Elements)>::type>
+	       enable_if<sizeof...(_UElements)
+			 == sizeof...(_Elements)>::type>
 	tuple(allocator_arg_t __tag, const _Alloc& __a,
 	      const tuple<_UElements...>& __in)
 	: _Inherited(__tag, __a,
@@ -418,8 +478,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	{ }
 
       template<typename _Alloc, typename... _UElements, typename = typename
-	       std::enable_if<sizeof...(_UElements)
-			      == sizeof...(_Elements)>::type>
+	       enable_if<sizeof...(_UElements)
+			 == sizeof...(_Elements)>::type>
 	tuple(allocator_arg_t __tag, const _Alloc& __a,
 	      tuple<_UElements...>&& __in)
 	: _Inherited(__tag, __a,
@@ -435,15 +495,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
       tuple&
       operator=(tuple&& __in)
-      noexcept(std::is_nothrow_move_assignable<_Inherited>::value)
+      noexcept(is_nothrow_move_assignable<_Inherited>::value)
       {
 	static_cast<_Inherited&>(*this) = std::move(__in);
 	return *this;
       }
 
       template<typename... _UElements, typename = typename
-	       std::enable_if<sizeof...(_UElements)
-			      == sizeof...(_Elements)>::type>
+	       enable_if<sizeof...(_UElements)
+			 == sizeof...(_Elements)>::type>
         tuple&
         operator=(const tuple<_UElements...>& __in)
         {
@@ -452,8 +512,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	}
 
       template<typename... _UElements, typename = typename
-	       std::enable_if<sizeof...(_UElements)
-			      == sizeof...(_Elements)>::type>
+	       enable_if<sizeof...(_UElements)
+			 == sizeof...(_Elements)>::type>
         tuple&
         operator=(tuple<_UElements...>&& __in)
         {
@@ -467,6 +527,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       { _Inherited::_M_swap(__in); }
     };
 
+  // Explicit specialization, zero-element tuple.
   template<>  
     class tuple<>
     {
@@ -474,7 +535,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       void swap(tuple&) noexcept { /* no-op */ }
     };
 
-  /// tuple (2-element), with construction and assignment from a pair.
+  /// Partial specialization, 2-element tuple.
+  /// Includes construction and assignment from a pair.
   template<typename _T1, typename _T2>
     class tuple<_T1, _T2> : public _Tuple_impl<0, _T1, _T2>
     {
@@ -488,32 +550,43 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       constexpr tuple(const _T1& __a1, const _T2& __a2)
       : _Inherited(__a1, __a2) { }
 
-      template<typename _U1, typename _U2>
+      template<typename _U1, typename _U2, typename = typename
+	       enable_if<__and_<is_convertible<_U1, _T1>,
+				is_convertible<_U2, _T2>>::value>::type>
         explicit
-        tuple(_U1&& __a1, _U2&& __a2)
+        constexpr tuple(_U1&& __a1, _U2&& __a2)
 	: _Inherited(std::forward<_U1>(__a1), std::forward<_U2>(__a2)) { }
 
       constexpr tuple(const tuple&) = default;
-      tuple(tuple&&) = default;
 
-      template<typename _U1, typename _U2>
-        tuple(const tuple<_U1, _U2>& __in)
+      constexpr tuple(tuple&&) = default;
+
+      template<typename _U1, typename _U2, typename = typename
+	enable_if<__and_<is_convertible<const _U1&, _T1>,
+			 is_convertible<const _U2&, _T2>>::value>::type>
+        constexpr tuple(const tuple<_U1, _U2>& __in)
 	: _Inherited(static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in)) { }
 
-      template<typename _U1, typename _U2>
-        tuple(tuple<_U1, _U2>&& __in)
+      template<typename _U1, typename _U2, typename = typename
+	       enable_if<__and_<is_convertible<_U1, _T1>,
+				is_convertible<_U2, _T2>>::value>::type>
+        constexpr tuple(tuple<_U1, _U2>&& __in)
 	: _Inherited(static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in)) { }
 
-      template<typename _U1, typename _U2>
-        tuple(const pair<_U1, _U2>& __in)
+      template<typename _U1, typename _U2, typename = typename
+	enable_if<__and_<is_convertible<const _U1&, _T1>,
+			 is_convertible<const _U2&, _T2>>::value>::type>
+        constexpr tuple(const pair<_U1, _U2>& __in)
 	: _Inherited(__in.first, __in.second) { }
 
-      template<typename _U1, typename _U2>
-        tuple(pair<_U1, _U2>&& __in)
+      template<typename _U1, typename _U2, typename = typename
+	       enable_if<__and_<is_convertible<_U1, _T1>,
+				is_convertible<_U2, _T2>>::value>::type>
+        constexpr tuple(pair<_U1, _U2>&& __in)
 	: _Inherited(std::forward<_U1>(__in.first),
 		     std::forward<_U2>(__in.second)) { }
 
-      // allocator-extended constructors
+      // Allocator-extended constructors.
 
       template<typename _Alloc>
 	tuple(allocator_arg_t __tag, const _Alloc& __a)
@@ -568,7 +641,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
       tuple&
       operator=(tuple&& __in)
-      noexcept(std::is_nothrow_move_assignable<_Inherited>::value)
+      noexcept(is_nothrow_move_assignable<_Inherited>::value)
       {
 	static_cast<_Inherited&>(*this) = std::move(__in);
 	return *this;
@@ -594,8 +667,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
         tuple&
         operator=(const pair<_U1, _U2>& __in)
         {
-	  this->_M_head() = __in.first;
-	  this->_M_tail()._M_head() = __in.second;
+	  this->_M_head(*this) = __in.first;
+	  this->_M_tail(*this)._M_head(*this) = __in.second;
 	  return *this;
 	}
 
@@ -603,108 +676,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
         tuple&
         operator=(pair<_U1, _U2>&& __in)
         {
-	  this->_M_head() = std::forward<_U1>(__in.first);
-	  this->_M_tail()._M_head() = std::forward<_U2>(__in.second);
-	  return *this;
-	}
-
-      void
-      swap(tuple& __in)
-      noexcept(noexcept(__in._M_swap(__in)))
-      { _Inherited::_M_swap(__in); }
-    };
-
-  /// tuple (1-element).
-  template<typename _T1>
-    class tuple<_T1> : public _Tuple_impl<0, _T1>
-    {
-      typedef _Tuple_impl<0, _T1> _Inherited;
-
-    public:
-      constexpr tuple()
-      : _Inherited() { }
-
-      explicit
-      constexpr tuple(const _T1& __a1)
-      : _Inherited(__a1) { }
-
-      template<typename _U1, typename = typename
-	       std::enable_if<std::is_constructible<_T1, _U1&&>::value>::type>
-        explicit
-        tuple(_U1&& __a1)
-	: _Inherited(std::forward<_U1>(__a1)) { }
-
-      constexpr tuple(const tuple&) = default;
-      tuple(tuple&&) = default;
-
-      template<typename _U1>
-        tuple(const tuple<_U1>& __in)
-	: _Inherited(static_cast<const _Tuple_impl<0, _U1>&>(__in)) { }
-
-      template<typename _U1>
-        tuple(tuple<_U1>&& __in)
-	: _Inherited(static_cast<_Tuple_impl<0, _U1>&&>(__in)) { }
-
-      // allocator-extended constructors
-
-      template<typename _Alloc>
-	tuple(allocator_arg_t __tag, const _Alloc& __a)
-	: _Inherited(__tag, __a) { }
-
-      template<typename _Alloc>
-	tuple(allocator_arg_t __tag, const _Alloc& __a, const _T1& __a1)
-	: _Inherited(__tag, __a, __a1) { }
-
-      // TODO: constrain for is_uses_allocator_constructible<_T1, _U1&&, _Alloc>
-      template<typename _Alloc, typename _U1>
-	tuple(allocator_arg_t __tag, const _Alloc& __a, _U1&& __a1)
-	: _Inherited(__tag, __a, std::forward<_U1>(__a1)) { }
-
-      template<typename _Alloc>
-	tuple(allocator_arg_t __tag, const _Alloc& __a, const tuple& __in)
-	: _Inherited(__tag, __a, static_cast<const _Inherited&>(__in)) { }
-
-      template<typename _Alloc>
-	tuple(allocator_arg_t __tag, const _Alloc& __a, tuple&& __in)
-	: _Inherited(__tag, __a, static_cast<_Inherited&&>(__in)) { }
-
-      template<typename _Alloc, typename _U1>
-	tuple(allocator_arg_t __tag, const _Alloc& __a, const tuple<_U1>& __in)
-	: _Inherited(__tag, __a, static_cast<const _Tuple_impl<0, _U1>&>(__in))
-       	{ }
-
-      template<typename _Alloc, typename _U1>
-	tuple(allocator_arg_t __tag, const _Alloc& __a, tuple<_U1>&& __in)
-	: _Inherited(__tag, __a, static_cast<_Tuple_impl<0, _U1>&&>(__in)) { }
-
-      tuple&
-      operator=(const tuple& __in)
-      {
-	static_cast<_Inherited&>(*this) = __in;
-	return *this;
-      }
-
-      tuple&
-      operator=(tuple&& __in)
-      noexcept(std::is_nothrow_move_assignable<_Inherited>::value)
-      {
-	static_cast<_Inherited&>(*this) = std::move(__in);
-	return *this;
-      }
-
-      template<typename _U1>
-        tuple&
-        operator=(const tuple<_U1>& __in)
-        {
-	  static_cast<_Inherited&>(*this) = __in;
-	  return *this;
-	}
-
-      template<typename _U1>
-        tuple&
-        operator=(tuple<_U1>&& __in)
-        {
-	  static_cast<_Inherited&>(*this) = std::move(__in);
+	  this->_M_head(*this) = std::forward<_U1>(__in.first);
+	  this->_M_tail(*this)._M_head(*this) = std::forward<_U2>(__in.second);
 	  return *this;
 	}
 
@@ -785,34 +758,34 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     : public integral_constant<std::size_t, sizeof...(_Elements)> { };
 
   template<std::size_t __i, typename _Head, typename... _Tail>
-    inline typename __add_ref<_Head>::type
+    constexpr typename __add_ref<_Head>::type
     __get_helper(_Tuple_impl<__i, _Head, _Tail...>& __t) noexcept
-    { return __t._M_head(); }
+    { return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); }
 
   template<std::size_t __i, typename _Head, typename... _Tail>
-    inline typename __add_c_ref<_Head>::type
+    constexpr typename __add_c_ref<_Head>::type
     __get_helper(const _Tuple_impl<__i, _Head, _Tail...>& __t) noexcept
-    { return __t._M_head(); }
+    { return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); }
 
   // Return a reference (const reference, rvalue reference) to the ith element
   // of a tuple.  Any const or non-const ref elements are returned with their
   // original type.
   template<std::size_t __i, typename... _Elements>
-    inline typename __add_ref<
+    constexpr typename __add_ref<
                       typename tuple_element<__i, tuple<_Elements...>>::type
                     >::type
     get(tuple<_Elements...>& __t) noexcept
     { return __get_helper<__i>(__t); }
 
   template<std::size_t __i, typename... _Elements>
-    inline typename __add_c_ref<
+    constexpr typename __add_c_ref<
                       typename tuple_element<__i, tuple<_Elements...>>::type
                     >::type
     get(const tuple<_Elements...>& __t) noexcept
     { return __get_helper<__i>(__t); }
 
   template<std::size_t __i, typename... _Elements>
-    inline typename __add_r_ref<
+    constexpr typename __add_r_ref<
                       typename tuple_element<__i, tuple<_Elements...>>::type
                     >::type
     get(tuple<_Elements...>&& __t) noexcept
@@ -827,13 +800,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   template<std::size_t __i, std::size_t __j, typename _Tp, typename _Up>
     struct __tuple_compare<0, __i, __j, _Tp, _Up>
     {
-      static bool __eq(const _Tp& __t, const _Up& __u)
+      static bool 
+      __eq(const _Tp& __t, const _Up& __u)
       {
 	return (get<__i>(__t) == get<__i>(__u) &&
 		__tuple_compare<0, __i + 1, __j, _Tp, _Up>::__eq(__t, __u));
       }
      
-      static bool __less(const _Tp& __t, const _Up& __u)
+      static bool 
+      __less(const _Tp& __t, const _Up& __u)
       {
 	return ((get<__i>(__t) < get<__i>(__u))
 		|| !(get<__i>(__u) < get<__i>(__t)) &&
@@ -844,11 +819,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   template<std::size_t __i, typename _Tp, typename _Up>
     struct __tuple_compare<0, __i, __i, _Tp, _Up>
     {
-      static bool __eq(const _Tp&, const _Up&)
-      { return true; }
+      static bool 
+      __eq(const _Tp&, const _Up&) { return true; }
      
-      static bool __less(const _Tp&, const _Up&)
-      { return false; }
+      static bool 
+      __less(const _Tp&, const _Up&) { return false; }
     };
 
   template<typename... _TElements, typename... _UElements>
@@ -899,7 +874,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
   // NB: DR 705.
   template<typename... _Elements>
-    inline tuple<typename __decay_and_strip<_Elements>::__type...>
+    constexpr tuple<typename __decay_and_strip<_Elements>::__type...>
     make_tuple(_Elements&&... __args)
     {
       typedef tuple<typename __decay_and_strip<_Elements>::__type...>
@@ -908,112 +883,188 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     }
 
   template<typename... _Elements>
-    inline tuple<_Elements&&...>
+    constexpr tuple<_Elements&&...>
     forward_as_tuple(_Elements&&... __args) noexcept
     { return tuple<_Elements&&...>(std::forward<_Elements>(__args)...); }
 
-  template<std::size_t...> struct __index_holder { };    
 
-  template<std::size_t __i, typename _IdxHolder, typename... _Elements>
-    struct __index_holder_impl;
+  template<typename, std::size_t> struct array;
+
+  template<std::size_t _Int, typename _Tp, std::size_t _Nm>
+    constexpr _Tp& get(array<_Tp, _Nm>&) noexcept;
 
-  template<std::size_t __i, std::size_t... _Indexes, typename _IdxHolder,
-	   typename... _Elements>
-    struct __index_holder_impl<__i, __index_holder<_Indexes...>,
-			       _IdxHolder, _Elements...> 
+  template<std::size_t _Int, typename _Tp, std::size_t _Nm>
+    constexpr _Tp&& get(array<_Tp, _Nm>&&) noexcept;
+
+  template<std::size_t _Int, typename _Tp, std::size_t _Nm>
+    constexpr const _Tp& get(const array<_Tp, _Nm>&) noexcept;
+
+  template<typename>
+    struct __is_tuple_like_impl : false_type
+    { };
+
+  template<typename... _Tps>
+    struct __is_tuple_like_impl<tuple<_Tps...>> : true_type
+    { };
+
+  template<typename _T1, typename _T2>
+    struct __is_tuple_like_impl<pair<_T1, _T2>> : true_type
+    { };
+
+  template<typename _Tp, std::size_t _Nm>
+    struct __is_tuple_like_impl<array<_Tp, _Nm>> : true_type
+    { };
+
+  // Internal type trait that allows us to sfinae-protect tuple_cat.
+  template<typename _Tp>
+    struct __is_tuple_like
+    : public __is_tuple_like_impl<typename std::remove_cv
+            <typename std::remove_reference<_Tp>::type>::type>::type
+    { };
+
+  // Stores a tuple of indices.  Also used by bind() to extract the elements
+  // in a tuple. 
+  template<std::size_t... _Indexes>
+    struct _Index_tuple
     {
-      typedef typename __index_holder_impl<__i + 1,
-					   __index_holder<_Indexes..., __i>,
-					   _Elements...>::type type;
+      typedef _Index_tuple<_Indexes..., sizeof...(_Indexes)> __next;
     };
- 
-  template<std::size_t __i, std::size_t... _Indexes>
-    struct __index_holder_impl<__i, __index_holder<_Indexes...> >
-    { typedef __index_holder<_Indexes...> type; };
 
-  template<typename... _Elements>
-    struct __make_index_holder 
-    : __index_holder_impl<0, __index_holder<>, _Elements...> { };
-    
-  template<typename... _TElements, std::size_t... _TIdx,
-	   typename... _UElements, std::size_t... _UIdx> 
-    inline tuple<_TElements..., _UElements...> 
-    __tuple_cat_helper(const tuple<_TElements...>& __t,
-		       const __index_holder<_TIdx...>&,
-                       const tuple<_UElements...>& __u,
-		       const __index_holder<_UIdx...>&)
-    { return tuple<_TElements..., _UElements...>(get<_TIdx>(__t)...,
-						 get<_UIdx>(__u)...); }
-
-  template<typename... _TElements, std::size_t... _TIdx,
-	   typename... _UElements, std::size_t... _UIdx> 
-    inline tuple<_TElements..., _UElements...> 
-    __tuple_cat_helper(tuple<_TElements...>&& __t,
-		       const __index_holder<_TIdx...>&, 
-		       const tuple<_UElements...>& __u,
-		       const __index_holder<_UIdx...>&)
-    { return tuple<_TElements..., _UElements...>
-	(std::forward<_TElements>(get<_TIdx>(__t))..., get<_UIdx>(__u)...); }
-
-  template<typename... _TElements, std::size_t... _TIdx,
-	   typename... _UElements, std::size_t... _UIdx>
-    inline tuple<_TElements..., _UElements...> 
-    __tuple_cat_helper(const tuple<_TElements...>& __t,
-		       const __index_holder<_TIdx...>&, 
-		       tuple<_UElements...>&& __u,
-		       const __index_holder<_UIdx...>&)
-    { return tuple<_TElements..., _UElements...>
-	(get<_TIdx>(__t)..., std::forward<_UElements>(get<_UIdx>(__u))...); }
-
-  template<typename... _TElements, std::size_t... _TIdx,
-	   typename... _UElements, std::size_t... _UIdx> 
-    inline tuple<_TElements..., _UElements...> 
-    __tuple_cat_helper(tuple<_TElements...>&& __t,
-		       const __index_holder<_TIdx...>&, 
-		       tuple<_UElements...>&& __u,
-		       const __index_holder<_UIdx...>&)
-    { return tuple<_TElements..., _UElements...>
-	(std::forward<_TElements>(get<_TIdx>(__t))...,
-	 std::forward<_UElements>(get<_UIdx>(__u))...); }
+  // Builds an _Index_tuple<0, 1, 2, ..., _Num-1>.
+  template<std::size_t _Num>
+    struct _Build_index_tuple
+    {
+      typedef typename _Build_index_tuple<_Num - 1>::__type::__next __type;
+    };
 
-  template<typename... _TElements, typename... _UElements>
-    inline tuple<_TElements..., _UElements...> 
-    tuple_cat(const tuple<_TElements...>& __t, const tuple<_UElements...>& __u)
+  template<>
+    struct _Build_index_tuple<0>
     {
-      return __tuple_cat_helper(__t, typename
-				__make_index_holder<_TElements...>::type(),
-				__u, typename
-				__make_index_holder<_UElements...>::type());
-    }
+      typedef _Index_tuple<> __type;
+    };
 
-  template<typename... _TElements, typename... _UElements>
-    inline tuple<_TElements..., _UElements...> 
-    tuple_cat(tuple<_TElements...>&& __t, const tuple<_UElements...>& __u)
+  template<std::size_t, typename, typename, std::size_t>
+    struct __make_tuple_impl;
+
+  template<std::size_t _Idx, typename _Tuple, typename... _Tp,
+           std::size_t _Nm>
+    struct __make_tuple_impl<_Idx, tuple<_Tp...>, _Tuple, _Nm>
     {
-      return __tuple_cat_helper(std::move(__t), typename
-				 __make_index_holder<_TElements...>::type(),
-				 __u, typename
-				 __make_index_holder<_UElements...>::type());
-    }
+      typedef typename __make_tuple_impl<_Idx + 1, tuple<_Tp...,
+	typename std::tuple_element<_Idx, _Tuple>::type>, _Tuple, _Nm>::__type
+      __type;
+    };
 
-  template<typename... _TElements, typename... _UElements>
-    inline tuple<_TElements..., _UElements...> 
-    tuple_cat(const tuple<_TElements...>& __t, tuple<_UElements...>&& __u)
+  template<std::size_t _Nm, typename _Tuple, typename... _Tp>
+    struct __make_tuple_impl<_Nm, tuple<_Tp...>, _Tuple, _Nm>
     {
-      return __tuple_cat_helper(__t, typename
-				__make_index_holder<_TElements...>::type(),
-				std::move(__u), typename
-				__make_index_holder<_UElements...>::type());
-    }
+      typedef tuple<_Tp...> __type;
+    };
 
-  template<typename... _TElements, typename... _UElements>
-    inline tuple<_TElements..., _UElements...>
-    tuple_cat(tuple<_TElements...>&& __t, tuple<_UElements...>&& __u)
+  template<typename _Tuple>
+    struct __do_make_tuple
+    : public __make_tuple_impl<0, tuple<>, _Tuple,
+                               std::tuple_size<_Tuple>::value>
+    { };
+
+  // Returns the std::tuple equivalent of a tuple-like type.
+  template<typename _Tuple>
+    struct __make_tuple
+    : public __do_make_tuple<typename std::remove_cv
+            <typename std::remove_reference<_Tuple>::type>::type>
+    { };
+
+  // Combines several std::tuple's into a single one.
+  template<typename...>
+    struct __combine_tuples;
+
+  template<>
+    struct __combine_tuples<>
+    {
+      typedef tuple<> __type;
+    };
+
+  template<typename... _Ts>
+    struct __combine_tuples<tuple<_Ts...>>
+    {
+      typedef tuple<_Ts...> __type;
+    };
+
+  template<typename... _T1s, typename... _T2s, typename... _Rem>
+    struct __combine_tuples<tuple<_T1s...>, tuple<_T2s...>, _Rem...>
+    {
+      typedef typename __combine_tuples<tuple<_T1s..., _T2s...>,
+					_Rem...>::__type __type;
+    };
+
+  // Computes the result type of tuple_cat given a set of tuple-like types.
+  template<typename... _Tpls>
+    struct __tuple_cat_result
+    {
+      typedef typename __combine_tuples
+        <typename __make_tuple<_Tpls>::__type...>::__type __type;
+    };
+
+  // Helper to determine the index set for the first tuple-like
+  // type of a given set.
+  template<typename...>
+    struct __make_1st_indices;
+
+  template<>
+    struct __make_1st_indices<>
     {
-      return __tuple_cat_helper(std::move(__t), typename
-				__make_index_holder<_TElements...>::type(),
-				std::move(__u), typename
-				__make_index_holder<_UElements...>::type());
+      typedef std::_Index_tuple<> __type;
+    };
+
+  template<typename _Tp, typename... _Tpls>
+    struct __make_1st_indices<_Tp, _Tpls...>
+    {
+      typedef typename std::_Build_index_tuple<std::tuple_size<
+	typename std::remove_reference<_Tp>::type>::value>::__type __type;
+    };
+
+  // Performs the actual concatenation by step-wise expanding tuple-like
+  // objects into the elements,  which are finally forwarded into the
+  // result tuple.
+  template<typename _Ret, typename _Indices, typename... _Tpls>
+    struct __tuple_concater;
+
+  template<typename _Ret, std::size_t... _Is, typename _Tp, typename... _Tpls>
+    struct __tuple_concater<_Ret, std::_Index_tuple<_Is...>, _Tp, _Tpls...>
+    {
+      template<typename... _Us>
+        static constexpr _Ret
+        _S_do(_Tp&& __tp, _Tpls&&... __tps, _Us&&... __us)
+        {
+	  typedef typename __make_1st_indices<_Tpls...>::__type __idx;
+	  typedef __tuple_concater<_Ret, __idx, _Tpls...>      __next;
+	  return __next::_S_do(std::forward<_Tpls>(__tps)...,
+			       std::forward<_Us>(__us)...,
+			       std::get<_Is>(std::forward<_Tp>(__tp))...);
+	}
+    };
+
+  template<typename _Ret>
+    struct __tuple_concater<_Ret, std::_Index_tuple<>>
+    {
+      template<typename... _Us>
+	static constexpr _Ret
+	_S_do(_Us&&... __us)
+        {
+	  return _Ret(std::forward<_Us>(__us)...);
+	}
+    };
+
+  template<typename... _Tpls, typename = typename
+           enable_if<__and_<__is_tuple_like<_Tpls>...>::value>::type>
+    constexpr auto
+    tuple_cat(_Tpls&&... __tpls)
+    -> typename __tuple_cat_result<_Tpls...>::__type
+    {
+      typedef typename __tuple_cat_result<_Tpls...>::__type __ret;
+      typedef typename __make_1st_indices<_Tpls...>::__type __idx;
+      typedef __tuple_concater<__ret, __idx, _Tpls...> __concater;
+      return __concater::_S_do(std::forward<_Tpls>(__tpls)...);
     }
 
   template<typename... _Elements>
@@ -1043,35 +1094,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   template<typename... _Types, typename _Alloc>
     struct uses_allocator<tuple<_Types...>, _Alloc> : true_type { };
 
-  /**
-   * Stores a tuple of indices. Used by bind() to extract the elements
-   * in a tuple. 
-   */
-  template<int... _Indexes>
-    struct _Index_tuple
-    {
-      typedef _Index_tuple<_Indexes..., sizeof...(_Indexes)> __next;
-    };
-
-  /// Builds an _Index_tuple<0, 1, 2, ..., _Num-1>.
-  template<std::size_t _Num>
-    struct _Build_index_tuple
-    {
-      typedef typename _Build_index_tuple<_Num-1>::__type::__next __type;
-    };
-
-  template<>
-    struct _Build_index_tuple<0>
-    {
-      typedef _Index_tuple<> __type;
-    };
-
   // See stl_pair.h...
   template<class _T1, class _T2>
     template<typename _Tp, typename... _Args>
       inline _Tp
-      pair<_T1, _T2>::
-      __cons(tuple<_Args...>&& __tuple)
+      pair<_T1, _T2>::__cons(tuple<_Args...>&& __tuple)
       {
 	typedef typename _Build_index_tuple<sizeof...(_Args)>::__type
 	  _Indexes;
@@ -1079,11 +1106,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       }
 
   template<class _T1, class _T2>
-    template<typename _Tp, typename... _Args, int... _Indexes>
+    template<typename _Tp, typename... _Args, std::size_t... _Indexes>
       inline _Tp
-      pair<_T1, _T2>::
-      __do_cons(tuple<_Args...>&& __tuple,
-		const _Index_tuple<_Indexes...>&)
+      pair<_T1, _T2>::__do_cons(tuple<_Args...>&& __tuple,
+				const _Index_tuple<_Indexes...>&)
       { return _Tp(std::forward<_Args>(get<_Indexes>(__tuple))...); }
 
 _GLIBCXX_END_NAMESPACE_VERSION