| //===----------------------------------------------------------------------===// |
| // |
| // 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 |
| // UNSUPPORTED: libcpp-no-concepts |
| // UNSUPPORTED: gcc-10 |
| |
| // template<common_with<I> I2> |
| // friend constexpr iter_difference_t<I2> operator-( |
| // const counted_iterator& x, const counted_iterator<I2>& y); |
| |
| #include <iterator> |
| |
| #include "test_macros.h" |
| #include "test_iterators.h" |
| |
| // This iterator is common_with forward_iterator but NOT comparable with it. |
| template <class It> |
| class CommonWithForwardIter |
| { |
| It it_; |
| |
| public: |
| typedef std::input_iterator_tag iterator_category; |
| typedef typename std::iterator_traits<It>::value_type value_type; |
| typedef typename std::iterator_traits<It>::difference_type difference_type; |
| typedef It pointer; |
| typedef typename std::iterator_traits<It>::reference reference; |
| |
| constexpr It base() const {return it_;} |
| |
| CommonWithForwardIter() = default; |
| explicit constexpr CommonWithForwardIter(It it) : it_(it) {} |
| constexpr CommonWithForwardIter(const forward_iterator<It>& it) : it_(it.base()) {} |
| |
| constexpr reference operator*() const {return *it_;} |
| |
| constexpr CommonWithForwardIter& operator++() {++it_; return *this;} |
| constexpr CommonWithForwardIter operator++(int) |
| {CommonWithForwardIter tmp(*this); ++(*this); return tmp;} |
| }; |
| |
| constexpr bool test() { |
| int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8}; |
| |
| { |
| std::counted_iterator iter1(random_access_iterator<int*>{buffer}, 8); |
| std::counted_iterator iter2(random_access_iterator<int*>{buffer + 4}, 4); |
| assert(iter1 - iter2 == -4); |
| assert(iter2 - iter1 == 4); |
| assert(iter1.count() == 8); |
| assert(iter2.count() == 4); |
| |
| ASSERT_SAME_TYPE(decltype(iter1 - iter2), std::iter_difference_t<int*>); |
| } |
| { |
| const std::counted_iterator iter1(random_access_iterator<int*>{buffer}, 8); |
| const std::counted_iterator iter2(random_access_iterator<int*>{buffer + 4}, 4); |
| assert(iter1 - iter2 == -4); |
| assert(iter2 - iter1 == 4); |
| assert(iter1.count() == 8); |
| assert(iter2.count() == 4); |
| |
| ASSERT_SAME_TYPE(decltype(iter1 - iter2), std::iter_difference_t<int*>); |
| } |
| { |
| std::counted_iterator iter1(contiguous_iterator<int*>{buffer}, 8); |
| std::counted_iterator iter2(contiguous_iterator<int*>{buffer + 2}, 6); |
| assert(iter1 - iter2 == -2); |
| assert(iter2 - iter1 == 2); |
| assert(iter1.count() == 8); |
| assert(iter2.count() == 6); |
| |
| ASSERT_SAME_TYPE(decltype(iter1 - iter2), std::iter_difference_t<int*>); |
| } |
| { |
| const std::counted_iterator iter1(contiguous_iterator<int*>{buffer}, 8); |
| const std::counted_iterator iter2(contiguous_iterator<int*>{buffer + 2}, 6); |
| assert(iter1 - iter2 == -2); |
| assert(iter2 - iter1 == 2); |
| assert(iter1.count() == 8); |
| assert(iter2.count() == 6); |
| |
| ASSERT_SAME_TYPE(decltype(iter1 - iter2), std::iter_difference_t<int*>); |
| } |
| // The minus operator works even if Iter is not a random_access_iterator because |
| // counted_iterator is able to implement it by subtracting the counts rather than |
| // the underlying iterators. |
| { |
| std::counted_iterator iter1(CommonWithForwardIter<int*>{buffer}, 8); |
| std::counted_iterator iter2(forward_iterator<int*>{buffer + 2}, 6); |
| assert(iter1 - iter2 == -2); |
| assert(iter2 - iter1 == 2); |
| assert(iter1.count() == 8); |
| assert(iter2.count() == 6); |
| |
| ASSERT_SAME_TYPE(decltype(iter1 - iter2), std::iter_difference_t<int*>); |
| } |
| { |
| const std::counted_iterator iter1(CommonWithForwardIter<int*>{buffer}, 8); |
| const std::counted_iterator iter2(forward_iterator<int*>{buffer + 2}, 6); |
| assert(iter1 - iter2 == -2); |
| assert(iter2 - iter1 == 2); |
| assert(iter1.count() == 8); |
| assert(iter2.count() == 6); |
| |
| ASSERT_SAME_TYPE(decltype(iter1 - iter2), std::iter_difference_t<int*>); |
| } |
| |
| return true; |
| } |
| |
| int main(int, char**) { |
| test(); |
| static_assert(test()); |
| |
| return 0; |
| } |