[libcxx] LWG2485: get() should be overloaded for const tuple&&. Patch from K-Ballo.

Review: http://reviews.llvm.org/D14839

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@255941 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 104 insertions, 2 deletions

diff --git a/include/__tuple b/include/__tuple
index 57581e842..8c3175977 100644
--- a/include/__tuple
+++ b/include/__tuple
@@ -86,6 +86,11 @@ template <size_t _Ip, class ..._Tp>
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 typename tuple_element<_Ip, tuple<_Tp...> >::type&&
 get(tuple<_Tp...>&&) _NOEXCEPT;
+
+template <size_t _Ip, class ..._Tp>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+const typename tuple_element<_Ip, tuple<_Tp...> >::type&&
+get(const tuple<_Tp...>&&) _NOEXCEPT;
 #endif
 
 // pair specializations
@@ -109,6 +114,11 @@ template <size_t _Ip, class _T1, class _T2>
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
 get(pair<_T1, _T2>&&) _NOEXCEPT;
+
+template <size_t _Ip, class _T1, class _T2>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+const typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
+get(const pair<_T1, _T2>&&) _NOEXCEPT;
 #endif
 
 // array specializations
@@ -132,6 +142,11 @@ template <size_t _Ip, class _Tp, size_t _Size>
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 _Tp&&
 get(array<_Tp, _Size>&&) _NOEXCEPT;
+
+template <size_t _Ip, class _Tp, size_t _Size>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+const _Tp&&
+get(const array<_Tp, _Size>&&) _NOEXCEPT;
 #endif
 
 #if !defined(_LIBCPP_HAS_NO_VARIADICS)
diff --git a/include/array b/include/array
index 360969051..8866eaf6b 100644
--- a/include/array
+++ b/include/array
@@ -95,6 +95,7 @@ template <size_t I, class T, size_t N> struct tuple_element<I, array<T, N>>;
 template <size_t I, class T, size_t N> T& get(array<T, N>&) noexcept; // constexpr in C++14
 template <size_t I, class T, size_t N> const T& get(const array<T, N>&) noexcept; // constexpr in C++14
 template <size_t I, class T, size_t N> T&& get(array<T, N>&&) noexcept; // constexpr in C++14
+template <size_t I, class T, size_t N> const T&& get(const array<T, N>&&) noexcept; // constexpr in C++14
 
 }  // std
 
@@ -324,6 +325,15 @@ get(array<_Tp, _Size>&& __a) _NOEXCEPT
     return _VSTD::move(__a.__elems_[_Ip]);
 }
 
+template <size_t _Ip, class _Tp, size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+const _Tp&&
+get(const array<_Tp, _Size>&& __a) _NOEXCEPT
+{
+    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (const std::array &&)");
+    return _VSTD::move(__a.__elems_[_Ip]);
+}
+
 #endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
 
 _LIBCPP_END_NAMESPACE_STD
diff --git a/include/tuple b/include/tuple
index 837be6fa1..cb1e27d93 100644
--- a/include/tuple
+++ b/include/tuple
@@ -95,6 +95,9 @@ template <size_t I, class... T>
 template <size_t I, class... T>
     typename tuple_element<I, tuple<T...>>::type&&
     get(tuple<T...>&&) noexcept; // constexpr in C++14
+template <size_t I, class... T>
+    const typename tuple_element<I, tuple<T...>>::type&&
+    get(const tuple<T...>&&) noexcept; // constexpr in C++14
 
 template <class T1, class... T>
     constexpr T1& get(tuple<T...>&) noexcept;  // C++14
@@ -102,6 +105,8 @@ template <class T1, class... T>
     constexpr const T1& get(const tuple<T...>&) noexcept;   // C++14
 template <class T1, class... T>
     constexpr T1&& get(tuple<T...>&&) noexcept;   // C++14
+template <class T1, class... T>
+    constexpr const T1&& get(const tuple<T...>&&) noexcept;   // C++14
 
 // 20.4.1.6, relational operators:
 template<class... T, class... U> bool operator==(const tuple<T...>&, const tuple<U...>&); // constexpr in C++14
@@ -507,6 +512,8 @@ class _LIBCPP_TYPE_VIS_ONLY tuple
         const typename tuple_element<_Jp, tuple<_Up...> >::type& get(const tuple<_Up...>&) _NOEXCEPT;
     template <size_t _Jp, class ..._Up> friend _LIBCPP_CONSTEXPR_AFTER_CXX11
         typename tuple_element<_Jp, tuple<_Up...> >::type&& get(tuple<_Up...>&&) _NOEXCEPT;
+    template <size_t _Jp, class ..._Up> friend _LIBCPP_CONSTEXPR_AFTER_CXX11
+        const typename tuple_element<_Jp, tuple<_Up...> >::type&& get(const tuple<_Up...>&&) _NOEXCEPT;
 public:
 
     template <bool _Dummy = true, class = typename enable_if<
@@ -766,6 +773,16 @@ get(tuple<_Tp...>&& __t) _NOEXCEPT
              static_cast<__tuple_leaf<_Ip, type>&&>(__t.base_).get());
 }
 
+template <size_t _Ip, class ..._Tp>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+const typename tuple_element<_Ip, tuple<_Tp...> >::type&&
+get(const tuple<_Tp...>&& __t) _NOEXCEPT
+{
+    typedef typename tuple_element<_Ip, tuple<_Tp...> >::type type;
+    return static_cast<const type&&>(
+             static_cast<const __tuple_leaf<_Ip, type>&&>(__t.base_).get());
+}
+
 #if _LIBCPP_STD_VER > 11
 // get by type
 template <typename _T1, size_t _Idx, typename... _Args>
@@ -822,6 +839,13 @@ constexpr _T1&& get(tuple<_Args...>&& __tup) noexcept
     return _VSTD::get<__find_exactly_one_t<_T1, _Args...>::value>(_VSTD::move(__tup));
 }
 
+template <class _T1, class... _Args>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr _T1 const&& get(tuple<_Args...> const&& __tup) noexcept
+{
+    return _VSTD::get<__find_exactly_one_t<_T1, _Args...>::value>(_VSTD::move(__tup));
+}
+
 #endif
 
 // tie
diff --git a/include/utility b/include/utility
index 8b376615f..4d0191c49 100644
--- a/include/utility
+++ b/include/utility
@@ -120,15 +120,34 @@ template<size_t I, class T1, class T2>
     typename tuple_element<I, pair<T1, T2> >::type&&
     get(pair<T1, T2>&&) noexcept; // constexpr in C++14
 
+template<size_t I, class T1, class T2>
+    const typename tuple_element<I, pair<T1, T2> >::type&&
+    get(const pair<T1, T2>&&) noexcept; // constexpr in C++14
+
 template<class T1, class T2>
     constexpr T1& get(pair<T1, T2>&) noexcept; // C++14
 
-template<size_t I, class T1, class T2>
+template<class T1, class T2>
     constexpr const T1& get(const pair<T1, T2>&) noexcept; // C++14
 
-template<size_t I, class T1, class T2>
+template<class T1, class T2>
     constexpr T1&& get(pair<T1, T2>&&) noexcept; // C++14
 
+template<class T1, class T2>
+    constexpr const T1&& get(const pair<T1, T2>&&) noexcept; // C++14
+
+template<class T1, class T2>
+    constexpr T1& get(pair<T2, T1>&) noexcept; // C++14
+
+template<class T1, class T2>
+    constexpr const T1& get(const pair<T2, T1>&) noexcept; // C++14
+
+template<class T1, class T2>
+    constexpr T1&& get(pair<T2, T1>&&) noexcept; // C++14
+
+template<class T1, class T2>
+    constexpr const T1&& get(const pair<T2, T1>&&) noexcept; // C++14
+
 // C++14
 
 template<class T, T... I>
@@ -560,6 +579,12 @@ struct __get_pair<0>
     _T1&&
     get(pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<_T1>(__p.first);}
 
+    template <class _T1, class _T2>
+    static
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    const _T1&&
+    get(const pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<const _T1>(__p.first);}
+
 #endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
 };
 
@@ -586,6 +611,12 @@ struct __get_pair<1>
     _T2&&
     get(pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<_T2>(__p.second);}
 
+    template <class _T1, class _T2>
+    static
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    const _T2&&
+    get(const pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<const _T2>(__p.second);}
+
 #endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
 };
 
@@ -615,6 +646,14 @@ get(pair<_T1, _T2>&& __p) _NOEXCEPT
     return __get_pair<_Ip>::get(_VSTD::move(__p));
 }
 
+template <size_t _Ip, class _T1, class _T2>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+const typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
+get(const pair<_T1, _T2>&& __p) _NOEXCEPT
+{
+    return __get_pair<_Ip>::get(_VSTD::move(__p));
+}
+
 #endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
 
 #if _LIBCPP_STD_VER > 11
@@ -641,6 +680,13 @@ constexpr _T1 && get(pair<_T1, _T2>&& __p) _NOEXCEPT
 
 template <class _T1, class _T2>
 inline _LIBCPP_INLINE_VISIBILITY
+constexpr _T1 const && get(pair<_T1, _T2> const&& __p) _NOEXCEPT
+{
+    return __get_pair<0>::get(_VSTD::move(__p));
+}
+
+template <class _T1, class _T2>
+inline _LIBCPP_INLINE_VISIBILITY
 constexpr _T1 & get(pair<_T2, _T1>& __p) _NOEXCEPT
 {
     return __get_pair<1>::get(__p);
@@ -660,6 +706,13 @@ constexpr _T1 && get(pair<_T2, _T1>&& __p) _NOEXCEPT
     return __get_pair<1>::get(_VSTD::move(__p));
 }
 
+template <class _T1, class _T2>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr _T1 const && get(pair<_T2, _T1> const&& __p) _NOEXCEPT
+{
+    return __get_pair<1>::get(_VSTD::move(__p));
+}
+
 #endif
 
 #if _LIBCPP_STD_VER > 11