65 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// constexpr auto end();12 13#include <cassert>14#include <ranges>15#include <type_traits>16#include <utility>17 18#include "test_iterators.h"19 20struct View : std::ranges::view_base {21 int* begin() const;22 int* end() const;23};24 25// Test that end is not const26template <class T>27concept HasEnd = requires(T t) { t.end(); };28 29struct Pred {30 constexpr bool operator()(int i) const { return i < 3; }31};32 33static_assert(HasEnd<std::ranges::drop_while_view<View, Pred>>);34static_assert(!HasEnd<const std::ranges::drop_while_view<View, Pred>>);35 36constexpr bool test() {37 // return iterator38 {39 int buffer[] = {1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1};40 std::ranges::drop_while_view dwv(buffer, Pred{});41 std::same_as<int*> decltype(auto) st = dwv.end();42 assert(st == buffer + 11);43 }44 45 // return sentinel46 {47 using Iter = int*;48 using Sent = sentinel_wrapper<Iter>;49 using Range = std::ranges::subrange<Iter, Sent>;50 int buffer[] = {1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1};51 Range range = {buffer, Sent{buffer + 11}};52 std::ranges::drop_while_view dwv(range, Pred{});53 std::same_as<Sent> decltype(auto) st = dwv.end();54 assert(base(st) == buffer + 11);55 }56 57 return true;58}59 60int main(int, char**) {61 test();62 static_assert(test());63 return 0;64}65