diff --git a/libstdc++-v3/include/bits/stl_pair.h b/libstdc++-v3/include/bits/stl_pair.h index 2de7439ac6a3..231d0bbd1f49 100644 --- a/libstdc++-v3/include/bits/stl_pair.h +++ b/libstdc++-v3/include/bits/stl_pair.h @@ -1315,12 +1315,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION template constexpr _Tp&& get(pair<_Tp, _Up>&& __p) noexcept - { return std::move(__p.first); } + { return std::forward<_Tp>(__p.first); } template constexpr const _Tp&& get(const pair<_Tp, _Up>&& __p) noexcept - { return std::move(__p.first); } + { return std::forward(__p.first); } template constexpr _Tp& @@ -1335,12 +1335,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION template constexpr _Tp&& get(pair<_Up, _Tp>&& __p) noexcept - { return std::move(__p.second); } + { return std::forward<_Tp>(__p.second); } template constexpr const _Tp&& get(const pair<_Up, _Tp>&& __p) noexcept - { return std::move(__p.second); } + { return std::forward(__p.second); } #endif // __glibcxx_tuples_by_type diff --git a/libstdc++-v3/testsuite/20_util/pair/astuple/get_by_type.cc b/libstdc++-v3/testsuite/20_util/pair/astuple/get_by_type.cc index 33ebf7a46b90..05a61c3f302c 100644 --- a/libstdc++-v3/testsuite/20_util/pair/astuple/get_by_type.cc +++ b/libstdc++-v3/testsuite/20_util/pair/astuple/get_by_type.cc @@ -33,3 +33,55 @@ void test01() const int&& cpsecond __attribute__((unused)) = std::get(std::move(cp)); } + +// PR libstdc++/121745 return of get(pair<_Up, _Tp>&& __p) may be ill-formed +void +test_pr121745(std::pair p) +{ + float& pfirst = std::get(std::move(p)); + int& psecond = std::get(std::move(p)); + + const auto& p2 = p; + float& p2first = std::get(std::move(p2)); + int& p2second = std::get(std::move(p2)); +} + +template +using get_t = decltype(std::get(std::declval())); + +// Check that get(Pair) returns Ret +template +constexpr bool verify = std::is_same, Ret>::value; + +template +void +check() +{ + // Overloads for accessing first member + static_assert( verify&, T1&>, + "T1& get(pair&)" ); + static_assert( verify&, const T1&>, + "const T1& get(const pair&)" ); + static_assert( verify&&, T1&&>, + "T1&& get(pair&&)" ); + static_assert( verify&&, const T1&&>, + "const T1&& get(const pair&&)" ); + + // Overloads for accessing second member + static_assert( verify&, T2&>, + "T2& get(pair&)" ); + static_assert( verify&, const T2&>, + "const T2& get(const pair&)" ); + static_assert( verify&&, T2&&>, + "T2&& get(pair&&)" ); + static_assert( verify&&, const T2&&>, + "const T2&& get(const pair&&)" ); +} + +void +test_all() +{ + check(); + check(); + check(); +}