Mercurial > hg > CbC > CbC_gcc
view libstdc++-v3/testsuite/18_support/comparisons/object/builtin-ptr-three-way.cc @ 152:2b5abeee2509
update gcc11
author | anatofuz |
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date | Mon, 25 May 2020 07:50:57 +0900 |
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// Copyright (C) 2020 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/>. // { dg-options "-std=gnu++2a" } // { dg-do compile { target c++2a } } #include <compare> void test01() { struct X { operator int() const { return 0; } operator long*() const { return nullptr; } } x; // Not three-way-comparable because of ambiguous conversion to int or long*: static_assert( ! std::three_way_comparable<X> ); // And therefore X is not three-way-comparable-with anything else // (because std::three_way_comparable_with<X, Y> requires that both // three_way_comparable<X> and three_way_comparable<Y> are true). static_assert( ! std::three_way_comparable_with<X, long*> ); long l; // But <=> is valid and resolves to a builtin operator comparing pointers: auto c = &l <=> x; // So std::compare_three_way should be usable: auto c2 = std::compare_three_way()(&l, x); }