LWG 1191

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@119545 91177308-0d34-0410-b5e6-96231b3b80d8

include/__tuple

@@ -83,6 +83,10 @@ template <size_t _Ip, class ..._Tp>
 const typename tuple_element<_Ip, tuple<_Tp...>>::type&
 get(const tuple<_Tp...>&);
 
+template <size_t _Ip, class ..._Tp>
+typename tuple_element<_Ip, tuple<_Tp...>>::type&&
+get(tuple<_Tp...>&&);
+
 template <size_t _Ip, class _T1, class _T2>
 typename tuple_element<_Ip, pair<_T1, _T2> >::type&
 get(pair<_T1, _T2>&);
@@ -91,6 +95,10 @@ template <size_t _Ip, class _T1, class _T2>
 const typename tuple_element<_Ip, pair<_T1, _T2> >::type&
 get(const pair<_T1, _T2>&);
 
+template <size_t _Ip, class _T1, class _T2>
+typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
+get(pair<_T1, _T2>&&);
+
 template <size_t _Ip, class _Tp, size_t _Size>
 _Tp&
 get(array<_Tp, _Size>&);
@@ -99,6 +107,10 @@ template <size_t _Ip, class _Tp, size_t _Size>
 const _Tp&
 get(const array<_Tp, _Size>&);
 
+template <size_t _Ip, class _Tp, size_t _Size>
+_Tp&&
+get(array<_Tp, _Size>&&);
+
 // __make_tuple_indices
 
 template <size_t...> struct __tuple_indices {};

include/array

@@ -94,6 +94,7 @@ template <class T, size_t N> struct tuple_size<array<T, N>>;
 template <int I, class T, size_t N> struct tuple_element<I, array<T, N>>;
 template <int I, class T, size_t N> T& get(array<T, N>&);
 template <int I, class T, size_t N> const T& get(const array<T, N>&);
+template <int I, class T, size_t N> T&& get(array<T, N>&&);
 
 }  // std
 
@@ -295,6 +296,18 @@ get(const array<_Tp, _Size>& __a)
     return __a[_Ip];
 }
 
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <size_t _Ip, class _Tp, size_t _Size>
+_LIBCPP_INLINE_VISIBILITY inline
+_Tp&&
+get(array<_Tp, _Size>&& __a)
+{
+    return _STD::move(__a[_Ip]);
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
 _LIBCPP_END_NAMESPACE_STD
 
 #endif  // _LIBCPP_ARRAY

include/tuple

@@ -88,6 +88,7 @@ template <intsize_t I, class... T> class tuple_element<I, tuple<T...>>;
 // 20.4.1.5, element access:
 template <intsize_t I, class... T> typename tuple_element<I, tuple<T...>>::type& get(tuple<T...>&);
 template <intsize_t I, class... T> typename tuple_element<I, tuple<T...>>::type const& get(const tuple<T...>&);
+template <intsize_t I, class... T> typename tuple_element<I, tuple<T...>>::type&& get(tuple<T...>&&);
 
 // 20.4.1.6, relational operators:
 template<class... T, class... U> bool operator==(const tuple<T...>&, const tuple<U...>&);
@@ -430,6 +431,8 @@ class _LIBCPP_VISIBLE tuple
         typename tuple_element<_Jp, tuple<_Up...>>::type& get(tuple<_Up...>&);
     template <size_t _Jp, class ..._Up> friend
         const typename tuple_element<_Jp, tuple<_Up...>>::type& get(const tuple<_Up...>&);
+    template <size_t _Jp, class ..._Up> friend
+        typename tuple_element<_Jp, tuple<_Up...>>::type&& get(tuple<_Up...>&&);
 public:
 
     _LIBCPP_INLINE_VISIBILITY
@@ -583,6 +586,15 @@ get(const tuple<_Tp...>& __t)
     return static_cast<const __tuple_leaf<_Ip, type>&>(__t.base_).get();
 }
 
+template <size_t _Ip, class ..._Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename tuple_element<_Ip, tuple<_Tp...>>::type&&
+get(tuple<_Tp...>&& __t)
+{
+    typedef typename tuple_element<_Ip, tuple<_Tp...>>::type type;
+    return static_cast<__tuple_leaf<_Ip, type>&&>(__t.base_).get();
+}
+
 // tie
 
 template <class ..._Tp>

include/utility

@@ -100,6 +100,10 @@ template<size_t I, class T1, class T2>
     const typename const tuple_element<I, std::pair<T1, T2> >::type&
     get(const std::pair<T1, T2>&);
 
+template<size_t I, class T1, class T2>
+    typename tuple_element<I, std::pair<T1, T2> >::type&&
+    get(std::pair<T1, T2>&&);
+
 }  // std
 
 */
@@ -425,6 +429,16 @@ struct __get_pair<0>
     _LIBCPP_INLINE_VISIBILITY
     const _T1&
     get(const pair<_T1, _T2>& __p) {return __p.first;}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    template <class _T1, class _T2>
+    static
+    _LIBCPP_INLINE_VISIBILITY
+    _T1&&
+    get(pair<_T1, _T2>&& __p) {return _STD::forward<_T1>(__p.first);}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
 };
 
 template <>
@@ -441,6 +455,16 @@ struct __get_pair<1>
     _LIBCPP_INLINE_VISIBILITY
     const _T2&
     get(const pair<_T1, _T2>& __p) {return __p.second;}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    template <class _T1, class _T2>
+    static
+    _LIBCPP_INLINE_VISIBILITY
+    _T2&&
+    get(pair<_T1, _T2>&& __p) {return _STD::forward<_T2>(__p.second);}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
 };
 
 template <size_t _Ip, class _T1, class _T2>
@@ -459,6 +483,18 @@ get(const pair<_T1, _T2>& __p)
     return __get_pair<_Ip>::get(__p);
 }
 
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <size_t _Ip, class _T1, class _T2>
+_LIBCPP_INLINE_VISIBILITY inline
+typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
+get(pair<_T1, _T2>&& __p)
+{
+    return __get_pair<_Ip>::get(_STD::move(__p));
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
 #endif  // _LIBCPP_HAS_NO_VARIADICS
 
 _LIBCPP_END_NAMESPACE_STD

test/containers/sequences/array/array.tuple/get_rv.pass.cpp

@@ -0,0 +1,29 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <array>
+
+// template <size_t I, class T, size_t N> T&& get(array<T, N>&& a);
+
+#include <array>
+#include <memory>
+#include <cassert>
+
+int main()
+{
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    {
+        typedef std::unique_ptr<double> T;
+        typedef std::array<T, 1> C;
+        C c = {std::unique_ptr<double>(new double(3.5))};
+        T t = std::get<0>(std::move(c));
+        assert(*t == 3.5);
+    }
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+}

test/utilities/tuple/tuple.tuple/tuple.elem/get_rv.pass.cpp

@@ -0,0 +1,30 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <tuple>
+
+// template <class... Types> class tuple;
+
+// template <size_t I, class... Types>
+//   typename tuple_element<I, tuple<Types...> >::type&&
+//   get(tuple<Types...>&& t);
+
+#include <tuple>
+#include <memory>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::tuple<std::unique_ptr<int> > T;
+        T t(std::unique_ptr<int>(new int(3)));
+        std::unique_ptr<int> p = std::get<0>(std::move(t));
+        assert(*p == 3);
+    }
+}

test/utilities/utility/pairs/pair.astuple/get_rv.pass.cpp

@@ -0,0 +1,32 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <utility>
+
+// template <class T1, class T2> struct pair
+
+// template<size_t I, class T1, class T2>
+//     typename tuple_element<I, std::pair<T1, T2> >::type&&
+//     get(pair<T1, T2>&&);
+
+#include <utility>
+#include <memory>
+#include <cassert>
+
+int main()
+{
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    {
+        typedef std::pair<std::unique_ptr<int>, short> P;
+        P p(std::unique_ptr<int>(new int(3)), 4);
+        std::unique_ptr<int> ptr = std::get<0>(std::move(p));
+        assert(*ptr == 3);
+    }
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+}