My fix for PR 60497 didn't cover the rvalue overloads of std::get.
I also noticed we don't handle comparisons properly if tuple elements have perverse overloaded comparison operators. Tested x86_64-linux, committed to trunk.
commit 0f87ec2cdf390a1234a8562e6b3aba95182a6951 Author: Jonathan Wakely <jwak...@redhat.com> Date: Tue May 13 11:43:32 2014 +0100 PR libstdc++/60497 * include/std/tuple (get, __tuple_compare): Qualify more calls to prevent ADL. Cast comparison results to bool. * testsuite/20_util/tuple/60497.cc: Test accessing rvalues. * testsuite/20_util/tuple/comparison_operators/overloaded.cc: New. diff --git a/libstdc++-v3/include/std/tuple b/libstdc++-v3/include/std/tuple index 03d87d7..5e8766c 100644 --- a/libstdc++-v3/include/std/tuple +++ b/libstdc++-v3/include/std/tuple @@ -775,7 +775,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION >::type get(tuple<_Elements...>&& __t) noexcept { return std::forward<typename tuple_element<__i, - tuple<_Elements...>>::type&&>(get<__i>(__t)); } + tuple<_Elements...>>::type&&>(std::get<__i>(__t)); } #if __cplusplus > 201103L template<typename _Head, size_t __i, typename... _Tail> @@ -815,16 +815,16 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION static constexpr 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)); + return bool(std::get<__i>(__t) == std::get<__i>(__u)) + && __tuple_compare<0, __i + 1, __j, _Tp, _Up>::__eq(__t, __u); } static constexpr bool __less(const _Tp& __t, const _Up& __u) { - return ((get<__i>(__t) < get<__i>(__u)) - || !(get<__i>(__u) < get<__i>(__t)) && - __tuple_compare<0, __i + 1, __j, _Tp, _Up>::__less(__t, __u)); + return bool(std::get<__i>(__t) < std::get<__i>(__u)) + || !bool(std::get<__i>(__u) < std::get<__i>(__t)) + && __tuple_compare<0, __i + 1, __j, _Tp, _Up>::__less(__t, __u); } }; diff --git a/libstdc++-v3/testsuite/20_util/tuple/60497.cc b/libstdc++-v3/testsuite/20_util/tuple/60497.cc index 76d4223..40d053b 100644 --- a/libstdc++-v3/testsuite/20_util/tuple/60497.cc +++ b/libstdc++-v3/testsuite/20_util/tuple/60497.cc @@ -35,3 +35,9 @@ auto a = std::get<0>(t); auto b = std::get<0>(ct); auto c = std::get<element_type>(t); auto d = std::get<element_type>(ct); + +// same again for rvalues +auto e = std::get<0>(std::move(t)); +auto f = std::get<0>(std::move(ct)); +auto g = std::get<element_type>(std::move(t)); +auto h = std::get<element_type>(std::move(ct)); diff --git a/libstdc++-v3/testsuite/20_util/tuple/comparison_operators/overloaded.cc b/libstdc++-v3/testsuite/20_util/tuple/comparison_operators/overloaded.cc new file mode 100644 index 0000000..0a343ae --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/tuple/comparison_operators/overloaded.cc @@ -0,0 +1,52 @@ +// { dg-options "-std=gnu++11" } +// { dg-do compile } + +// Copyright (C) 2014 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. + +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. + +// You should have received a copy of the GNU General Public License along +// with this library; see the file COPYING3. If not see +// <http://www.gnu.org/licenses/>. + +#include <tuple> + +// A type that is contextually convertible to bool but cannot be used with +// the usual logical operators, and/or/not. +struct TwistedLogic { + bool value; + + explicit operator bool() const noexcept { return value; } +}; + +template<typename T> +bool operator&&(const T&, TwistedLogic) = delete; + +template<typename T> +bool operator&&(TwistedLogic, const T&) = delete; + +template<typename T> +bool operator||(const T&, TwistedLogic) = delete; + +template<typename T> +bool operator||(TwistedLogic, const T&) = delete; + +bool operator!(TwistedLogic) noexcept = delete; + +struct Compares {}; + +TwistedLogic operator==(const Compares&, const Compares&) { return {true}; } +TwistedLogic operator<(const Compares&, const Compares&) { return {false}; } + +auto a = std::make_tuple(nullptr, Compares{}, 2, 'U'); +auto b = a == a; +auto c = a < a;