| // 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::crbegin)); |
| |
| struct R1 |
| { |
| int i = 0; |
| int j = 0; |
| |
| const int* rbegin() const { return &i; } |
| friend const int* rbegin(const R1&& r) { return &r.j; } |
| }; |
| |
| struct R1V // view on an R1 |
| { |
| R1& r; |
| |
| friend const long* rbegin(R1V&); // this is not defined |
| friend const int* rbegin(const R1V& rv) noexcept { return rv.r.rbegin(); } |
| }; |
| |
| // Allow ranges::end to work with R1V&& |
| template<> constexpr bool std::ranges::enable_borrowed_range<R1V> = true; |
| |
| void |
| test01() |
| { |
| R1 r; |
| const R1& c = r; |
| VERIFY( std::ranges::crbegin(r) == std::ranges::rbegin(c) ); |
| VERIFY( std::ranges::crbegin(c) == std::ranges::rbegin(c) ); |
| |
| R1V v{r}; |
| const R1V cv{r}; |
| VERIFY( std::ranges::crbegin(std::move(v)) == std::ranges::rbegin(c) ); |
| VERIFY( std::ranges::crbegin(std::move(cv)) == std::ranges::rbegin(c) ); |
| } |
| |
| struct R2 |
| { |
| int a[2] = { }; |
| long l[2] = { }; |
| |
| const int* begin() const { return a; } |
| const int* end() const { return a + 2; } |
| |
| friend const long* begin(const R2&&); // not defined |
| friend const long* end(const R2&&); // not defined |
| }; |
| |
| // N.B. this is a lie, rbegin on an R2 rvalue will return a dangling pointer. |
| template<> constexpr bool std::ranges::enable_borrowed_range<R2> = true; |
| |
| void |
| test02() |
| { |
| R2 r; |
| const R2& c = r; |
| VERIFY( std::ranges::crbegin(r) == std::ranges::rbegin(c) ); |
| VERIFY( std::ranges::crbegin(c) == std::ranges::rbegin(c) ); |
| |
| VERIFY( std::ranges::crbegin(std::move(r)) == std::ranges::rbegin(c) ); |
| VERIFY( std::ranges::crbegin(std::move(c)) == std::ranges::rbegin(c) ); |
| } |
| |
| int |
| main() |
| { |
| test01(); |
| test02(); |
| } |