75 lines · cpp
1//===----------------------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9// UNSUPPORTED: c++03, c++11, c++14, c++1710 11// friend constexpr void iter_swap(const iterator& x, const iterator& y);12 13#include <cassert>14#include <ranges>15 16#include "../types.h"17 18using NonSwappableView = BufferView<copying_iterator<int*>>;19static_assert(std::ranges::input_range<NonSwappableView>);20static_assert(!std::indirectly_swappable<std::ranges::iterator_t<NonSwappableView>>);21 22constexpr bool test() {23 int buffer[4][4] = {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10, 11, 12}, {13, 14, 15, 16}};24 25 {26 std::ranges::join_view jv(buffer);27 auto iter1 = jv.begin();28 auto iter2 = std::next(jv.begin());29 assert(buffer[0][0] == 1);30 assert(buffer[0][1] == 2);31 std::ranges::iter_swap(iter1, iter2);32 assert(buffer[0][0] == 2);33 assert(buffer[0][1] == 1);34 35 static_assert(noexcept(std::ranges::iter_swap(iter1, iter2)));36 }37 38 {39 // iter_move calls inner's iter_swap40 IterMoveSwapAwareView inners[1] = {buffer[0]};41 std::ranges::join_view jv(inners);42 auto it1 = jv.begin();43 auto it2 = std::ranges::next(it1);44 45 const auto& iter_swap_called_times = jv.base().begin()->iter_swap_called;46 47 assert(iter_swap_called_times == 0);48 assert(buffer[0][0] == 2);49 assert(buffer[0][1] == 1);50 51 std::ranges::iter_swap(it1, it2);52 53 assert(buffer[0][0] == 1);54 assert(buffer[0][1] == 2);55 assert(iter_swap_called_times == 1);56 }57 58 {59 // LWG3517 `join_view::iterator`'s `iter_swap` is underconstrained60 // `iter_swap` should not be defined if Inner's iterator does not indirectly_swappable61 NonSwappableView inners[2] = {buffer[0], buffer[1]};62 std::ranges::join_view jv(inners);63 using Iter = std::ranges::iterator_t<decltype(jv)>;64 static_assert(!std::indirectly_swappable<Iter>);65 }66 return true;67}68 69int main(int, char**) {70 test();71 static_assert(test());72 73 return 0;74}75