| // Copyright (C) 2019-2021 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 run { target c++2a } } |
| |
| #include <ranges> |
| #include <testsuite_hooks.h> |
| #include <testsuite_iterators.h> |
| |
| static_assert(__gnu_test::is_customization_point_object(std::ranges::empty)); |
| |
| using std::same_as; |
| |
| void |
| test01() |
| { |
| struct R |
| { |
| constexpr int empty() const & { return 0; } |
| constexpr const void* empty() const && { return this; } |
| }; |
| constexpr R r; |
| static_assert( !std::ranges::empty(r) ); |
| static_assert( same_as<decltype(std::ranges::empty(r)), bool> ); |
| // PR libstdc++/100824 |
| // ranges::empty should treat the subexpression as an lvalue |
| static_assert( !std::ranges::empty(std::move(r)) ); |
| static_assert( same_as<decltype(std::ranges::empty(std::move(r))), bool> ); |
| } |
| |
| void |
| test02() |
| { |
| using __gnu_test::test_range; |
| using __gnu_test::test_sized_range; |
| using __gnu_test::random_access_iterator_wrapper; |
| using __gnu_test::forward_iterator_wrapper; |
| using __gnu_test::input_iterator_wrapper; |
| using __gnu_test::output_iterator_wrapper; |
| |
| int a[] = { 0, 1 }; |
| VERIFY( !std::ranges::empty(a) ); |
| |
| test_range<int, random_access_iterator_wrapper> r(a); |
| VERIFY( !std::ranges::empty(r) ); |
| |
| test_range<int, forward_iterator_wrapper> i(a); |
| VERIFY( !std::ranges::empty(i) ); |
| |
| test_sized_range<int, random_access_iterator_wrapper> sr(a); |
| VERIFY( !std::ranges::empty(sr) ); |
| |
| test_sized_range<int, input_iterator_wrapper> si(a); |
| VERIFY( !std::ranges::empty(si) ); |
| |
| test_sized_range<int, output_iterator_wrapper> so(a); |
| VERIFY( !std::ranges::empty(so) ); |
| } |
| |
| void |
| test03() |
| { |
| // PR libstdc++/100824 |
| // ranges::empty should treat the subexpression as an lvalue |
| |
| struct R |
| { |
| constexpr bool empty() & { return true; } |
| }; |
| static_assert( std::ranges::empty(R{}) ); |
| |
| struct R2 |
| { |
| constexpr unsigned size() & { return 0; } |
| }; |
| static_assert( std::ranges::empty(R2{}) ); |
| } |
| |
| void |
| test04() |
| { |
| struct E1 |
| { |
| bool empty() const noexcept { return {}; } |
| }; |
| |
| static_assert( noexcept(std::ranges::empty(E1{})) ); |
| |
| struct E2 |
| { |
| bool empty() const noexcept(false) { return {}; } |
| }; |
| |
| static_assert( ! noexcept(std::ranges::empty(E2{})) ); |
| |
| struct E3 |
| { |
| struct B |
| { |
| explicit operator bool() const noexcept(false) { return true; } |
| }; |
| |
| B empty() const noexcept { return {}; } |
| }; |
| |
| static_assert( ! noexcept(std::ranges::empty(E3{})) ); |
| } |
| |
| int |
| main() |
| { |
| test01(); |
| test02(); |
| test03(); |
| test04(); |
| } |