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-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 // UNSUPPORTED: c++03, c++11, c++14, c++17 10 // UNSUPPORTED: libcpp-has-no-incomplete-ranges 11 12 // friend constexpr void iter_swap(const iterator& x, const iterator& y); 13 14 #include <cassert> 15 #include <ranges> 16 17 #include "../types.h" 18 19 using NonSwappableView = BufferView<copying_iterator<int*>>; 20 static_assert(std::ranges::input_range<NonSwappableView>); 21 static_assert(!std::indirectly_swappable<std::ranges::iterator_t<NonSwappableView>>); 22 23 constexpr bool test() { 24 int buffer[4][4] = {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10, 11, 12}, {13, 14, 15, 16}}; 25 26 { 27 std::ranges::join_view jv(buffer); 28 auto iter1 = jv.begin(); 29 auto iter2 = std::next(jv.begin()); 30 assert(buffer[0][0] == 1); 31 assert(buffer[0][1] == 2); 32 std::ranges::iter_swap(iter1, iter2); 33 assert(buffer[0][0] == 2); 34 assert(buffer[0][1] == 1); 35 36 static_assert(noexcept(std::ranges::iter_swap(iter1, iter2))); 37 } 38 39 { 40 // iter_move calls inner's iter_swap 41 IterMoveSwapAwareView inners[1] = {buffer[0]}; 42 std::ranges::join_view jv(inners); 43 auto it1 = jv.begin(); 44 auto it2 = std::ranges::next(it1); 45 46 const auto& iter_swap_called_times = jv.base().begin()->iter_swap_called; 47 48 assert(iter_swap_called_times == 0); 49 assert(buffer[0][0] == 2); 50 assert(buffer[0][1] == 1); 51 52 std::ranges::iter_swap(it1, it2); 53 54 assert(buffer[0][0] == 1); 55 assert(buffer[0][1] == 2); 56 assert(iter_swap_called_times == 1); 57 } 58 59 { 60 // LWG3517 `join_view::iterator`'s `iter_swap` is underconstrained 61 // `iter_swap` should not be defined if Inner's iterator does not indirectly_swappable 62 NonSwappableView inners[2] = {buffer[0], buffer[1]}; 63 std::ranges::join_view jv(inners); 64 using Iter = std::ranges::iterator_t<decltype(jv)>; 65 static_assert(!std::indirectly_swappable<Iter>); 66 } 67 return true; 68 } 69 70 int main(int, char**) { 71 test(); 72 static_assert(test()); 73 74 return 0; 75 } 76