| // 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::rbegin)); |
| |
| struct R1 |
| { |
| int i = 0; |
| int j = 0; |
| |
| constexpr const int* rbegin() const { return &i; } |
| friend constexpr const int* rbegin(const R1&& r) { return &r.j; } |
| }; |
| |
| // N.B. this is a lie, rbegin on an R1 rvalue will return a dangling pointer. |
| template<> constexpr bool std::ranges::enable_borrowed_range<R1> = true; |
| |
| void |
| test01() |
| { |
| constexpr R1 r; |
| // decay-copy(t.rbegin()) if it is a valid expression |
| // and its type I models input_or_output_iterator. |
| static_assert( std::ranges::rbegin(r) == &r.i ); |
| static_assert( std::ranges::rbegin(std::move(r)) == &r.i ); |
| } |
| |
| struct R2 |
| { |
| int a[2] = { }; |
| |
| constexpr const int* begin() const { return a; } |
| constexpr const int* end() const { return a + 2; } |
| |
| friend constexpr const long* begin(const R2&&); // not defined |
| friend constexpr const long* end(const R2&&); // not defined |
| }; |
| |
| // N.B. this is a lie, begin/end on an R2 rvalue will return a dangling pointer. |
| template<> constexpr bool std::ranges::enable_borrowed_range<R2> = true; |
| |
| void |
| test02() |
| { |
| constexpr R2 r; |
| // Otherwise, decay-copy(rbegin(t)) if it is a valid expression |
| // and its type I models input_or_output_iterator [...] |
| static_assert( std::ranges::rbegin(r) |
| == std::make_reverse_iterator(std::ranges::end(r)) ); |
| static_assert( std::ranges::rbegin(std::move(r)) |
| == std::make_reverse_iterator(std::ranges::end(std::move(r))) ); |
| } |
| |
| void |
| test03() |
| { |
| struct R3 |
| : __gnu_test::test_range<int, __gnu_test::bidirectional_iterator_wrapper> |
| { |
| R3(int (&a)[2]) : test_range(a) { } |
| |
| using test_range::begin; |
| |
| // Replace test_range::end() to return same type as begin() |
| // so ranges::rbegin will wrap it in a reverse_iterator . |
| auto end() & |
| { |
| using __gnu_test::bidirectional_iterator_wrapper; |
| return bidirectional_iterator_wrapper<int>(bounds.last, &bounds); |
| } |
| }; |
| |
| int a[2] = { }; |
| R3 r(a); |
| |
| // Otherwise, make_reverse_iterator(ranges::end(t)) if both ranges::begin(t) |
| // and ranges::end(t) are valid expressions of the same type I which models |
| // bidirectional_iterator. |
| |
| VERIFY( std::ranges::rbegin(r) == std::make_reverse_iterator(std::ranges::end(r)) ); |
| } |
| |
| int |
| main() |
| { |
| test01(); |
| test02(); |
| test03(); |
| } |