64 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 iter_difference_t<W> operator-(const iterator& x, const sentinel& y)12// requires sized_sentinel_for<Bound, W>;13// friend constexpr iter_difference_t<W> operator-(const sentinel& x, const iterator& y)14// requires sized_sentinel_for<Bound, W>;15 16#include <ranges>17#include <cassert>18 19#include "test_macros.h"20#include "test_iterators.h"21#include "../types.h"22 23template<class T>24concept MinusInvocable = requires(std::ranges::iota_view<T, IntSentinelWith<T>> io) {25 io.end() - io.begin();26};27 28constexpr bool test() {29 int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8};30 31 {32 auto outIter = random_access_iterator<int*>(buffer);33 std::ranges::iota_view<random_access_iterator<int*>, IntSentinelWith<random_access_iterator<int*>>> io(34 outIter, IntSentinelWith<random_access_iterator<int*>>(std::ranges::next(outIter, 8)));35 auto iter = io.begin();36 auto sent = io.end();37 assert(iter - sent == -8);38 assert(sent - iter == 8);39 }40 {41 auto outIter = random_access_iterator<int*>(buffer);42 const std::ranges::iota_view<random_access_iterator<int*>, IntSentinelWith<random_access_iterator<int*>>> io(43 outIter, IntSentinelWith<random_access_iterator<int*>>(std::ranges::next(outIter, 8)));44 const auto iter = io.begin();45 const auto sent = io.end();46 assert(iter - sent == -8);47 assert(sent - iter == 8);48 }49 50 {51 // The minus operator requires that "W" is an input_or_output_iterator.52 static_assert(!MinusInvocable<int>);53 }54 55 return true;56}57 58int main(int, char**) {59 test();60 static_assert(test());61 62 return 0;63}64