| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // UNSUPPORTED: c++03, c++11, c++14, c++17 |
| |
| // <algorithm> |
| |
| // template<bidirectional_iterator I, sentinel_for<I> S> |
| // requires permutable<I> |
| // constexpr I ranges::reverse(I first, S last); |
| // template<bidirectional_range R> |
| // requires permutable<iterator_t<R>> |
| // constexpr borrowed_iterator_t<R> ranges::reverse(R&& r); |
| |
| #include <algorithm> |
| #include <array> |
| #include <concepts> |
| #include <ranges> |
| |
| #include "almost_satisfies_types.h" |
| #include "MoveOnly.h" |
| #include "test_iterators.h" |
| |
| template <class Iter, class Sent = sentinel_wrapper<Iter>> |
| concept HasReverseIt = requires (Iter first, Sent last) { std::ranges::reverse(first, last); }; |
| |
| static_assert(HasReverseIt<int*>); |
| static_assert(!HasReverseIt<BidirectionalIteratorNotDerivedFrom>); |
| static_assert(!HasReverseIt<BidirectionalIteratorNotDecrementable>); |
| static_assert(!HasReverseIt<PermutableNotForwardIterator>); |
| static_assert(!HasReverseIt<PermutableNotSwappable>); |
| |
| |
| template <class Range> |
| concept HasReverseR = requires (Range range) { std::ranges::reverse(range); }; |
| |
| static_assert(HasReverseR<UncheckedRange<int*>>); |
| static_assert(!HasReverseR<BidirectionalRangeNotDerivedFrom>); |
| static_assert(!HasReverseR<BidirectionalRangeNotDecrementable>); |
| static_assert(!HasReverseR<PermutableRangeNotForwardIterator>); |
| static_assert(!HasReverseR<PermutableRangeNotSwappable>); |
| |
| template <class Iter, class Sent, std::size_t N> |
| constexpr void test(std::array<int, N> value, std::array<int, N> expected) { |
| { |
| auto val = value; |
| std::same_as<Iter> decltype(auto) ret = std::ranges::reverse(Iter(val.data()), Sent(Iter(val.data() + val.size()))); |
| assert(val == expected); |
| assert(base(ret) == val.data() + val.size()); |
| } |
| { |
| auto val = value; |
| auto range = std::ranges::subrange(Iter(val.data()), Sent(Iter(val.data() + val.size()))); |
| std::same_as<Iter> decltype(auto) ret = std::ranges::reverse(range); |
| assert(val == expected); |
| assert(base(ret) == val.data() + val.size()); |
| } |
| } |
| |
| template <class Iter, class Sent = Iter> |
| constexpr void test_iterators() { |
| // simple test |
| test<Iter, Sent, 4>({1, 2, 3, 4}, {4, 3, 2, 1}); |
| // check that an odd number of elements works |
| test<Iter, Sent, 7>({1, 2, 3, 4, 5, 6, 7}, {7, 6, 5, 4, 3, 2, 1}); |
| // check that an empty range works |
| test<Iter, Sent, 0>({}, {}); |
| // check that a single element works |
| test<Iter, Sent, 1>({5}, {5}); |
| } |
| |
| struct SwapCounter { |
| int* counter; |
| constexpr SwapCounter(int* counter_) : counter(counter_) {} |
| friend constexpr void swap(SwapCounter& lhs, SwapCounter&) { ++*lhs.counter; } |
| }; |
| |
| constexpr bool test() { |
| test_iterators<bidirectional_iterator<int*>>(); |
| test_iterators<bidirectional_iterator<int*>, sentinel_wrapper<bidirectional_iterator<int*>>>(); |
| test_iterators<random_access_iterator<int*>>(); |
| test_iterators<random_access_iterator<int*>, sentinel_wrapper<random_access_iterator<int*>>>(); |
| test_iterators<contiguous_iterator<int*>>(); |
| test_iterators<contiguous_iterator<int*>, sentinel_wrapper<contiguous_iterator<int*>>>(); |
| test_iterators<int*>(); |
| |
| test_iterators<ProxyIterator<bidirectional_iterator<int*>>>(); |
| test_iterators<ProxyIterator<random_access_iterator<int*>>>(); |
| test_iterators<ProxyIterator<contiguous_iterator<int*>>>(); |
| |
| // check that std::ranges::dangling is returned |
| { |
| [[maybe_unused]] std::same_as<std::ranges::dangling> auto ret = std::ranges::reverse(std::array {1, 2, 3, 4}); |
| } |
| |
| { |
| { |
| int counter = 0; |
| SwapCounter a[] = {&counter, &counter, &counter, &counter}; |
| std::ranges::reverse(a); |
| assert(counter == 2); |
| } |
| { |
| int counter = 0; |
| SwapCounter a[] = {&counter, &counter, &counter, &counter}; |
| std::ranges::reverse(a, a + 4); |
| assert(counter == 2); |
| } |
| } |
| |
| // Move only types work for ProxyIterator |
| { |
| { |
| MoveOnly a[] = {1, 2, 3}; |
| ProxyRange proxyA{a}; |
| std::ranges::reverse(proxyA.begin(), proxyA.end()); |
| assert(a[0].get() == 3); |
| assert(a[1].get() == 2); |
| assert(a[2].get() == 1); |
| } |
| { |
| MoveOnly a[] = {1, 2, 3}; |
| ProxyRange proxyA{a}; |
| std::ranges::reverse(proxyA); |
| assert(a[0].get() == 3); |
| assert(a[1].get() == 2); |
| assert(a[2].get() == 1); |
| } |
| } |
| |
| return true; |
| } |
| |
| int main(int, char**) { |
| test(); |
| static_assert(test()); |
| |
| return 0; |
| } |