88 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 iterator operator+(iterator i, difference_type n)12// requires advanceable<W>;13// friend constexpr iterator operator+(difference_type n, iterator i)14// requires advanceable<W>;15 16#include <cassert>17#include <ranges>18#include <type_traits>19 20#include "test_macros.h"21#include "../types.h"22 23constexpr bool test() {24 // When "_Start" is signed integer like.25 {26 std::ranges::iota_view<int> io(0);27 auto iter1 = io.begin();28 auto iter2 = io.begin();29 assert(iter1 == iter2);30 assert(iter1 + 5 != iter2);31 assert(iter1 + 5 == std::ranges::next(iter2, 5));32 33 static_assert(std::is_reference_v<decltype(iter2 += 5)>);34 }35 36 // When "_Start" is not integer like.37 {38 std::ranges::iota_view io(SomeInt(0));39 auto iter1 = io.begin();40 auto iter2 = io.begin();41 assert(iter1 == iter2);42 assert(iter1 + 5 != iter2);43 assert(iter1 + 5 == std::ranges::next(iter2, 5));44 45 static_assert(std::is_reference_v<decltype(iter2 += 5)>);46 }47 48 // When "_Start" is unsigned integer like and n is greater than or equal to zero.49 {50 std::ranges::iota_view<unsigned> io(0);51 auto iter1 = io.begin();52 auto iter2 = io.begin();53 assert(iter1 == iter2);54 assert(iter1 + 5 != iter2);55 assert(iter1 + 5 == std::ranges::next(iter2, 5));56 57 static_assert(std::is_reference_v<decltype(iter2 += 5)>);58 }59 {60 std::ranges::iota_view<unsigned> io(0);61 auto iter1 = io.begin();62 auto iter2 = io.begin();63 assert(iter1 == iter2);64 assert(iter1 + 0 == iter2);65 }66 67 // When "_Start" is unsigned integer like and n is less than zero.68 {69 std::ranges::iota_view<unsigned> io(0);70 auto iter1 = io.begin();71 auto iter2 = io.begin();72 assert(iter1 == iter2);73 assert(iter1 + 5 != iter2);74 assert(iter1 + 5 == std::ranges::next(iter2, 5));75 76 static_assert(std::is_reference_v<decltype(iter2 += 5)>);77 }78 79 return true;80}81 82int main(int, char**) {83 test();84 static_assert(test());85 86 return 0;87}88