87 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 explicit sentinel(sentinel_t<Base> end, const Pred* pred);12 13#include <cassert>14#include <ranges>15#include <utility>16 17#include "../types.h"18 19struct Sent {20 int i;21 22 friend constexpr bool operator==(int* iter, const Sent& s) { return s.i > *iter; }23};24 25struct Range : std::ranges::view_base {26 int* begin() const;27 Sent end();28};29 30struct Pred {31 bool operator()(int i) const;32};33 34// Test explicit35template <class T>36void conversion_test(T);37 38template <class T, class... Args>39concept ImplicitlyConstructible = requires(Args&&... args) { conversion_test<T>({std::forward<Args>(args)...}); };40static_assert(ImplicitlyConstructible<int, int>);41 42static_assert(std::is_constructible_v<std::ranges::sentinel_t<std::ranges::take_while_view<Range, Pred>>,43 std::ranges::sentinel_t<Range>,44 const Pred*>);45static_assert(!ImplicitlyConstructible<std::ranges::sentinel_t<std::ranges::take_while_view<Range, Pred>>,46 std::ranges::sentinel_t<Range>,47 const Pred*>);48 49constexpr bool test() {50 // base is init correctly51 {52 using R = std::ranges::take_while_view<Range, bool (*)(int)>;53 using Sentinel = std::ranges::sentinel_t<R>;54 55 Sentinel s1(Sent{5}, nullptr);56 assert(s1.base().i == 5);57 }58 59 // pred is init correctly60 {61 bool called = false;62 auto pred = [&](int) {63 called = true;64 return false;65 };66 67 using R = std::ranges::take_while_view<Range, decltype(pred)>;68 using Sentinel = std::ranges::sentinel_t<R>;69 70 int i = 10;71 int* iter = &i;72 Sentinel s(Sent{0}, &pred);73 74 bool b = iter == s;75 assert(called);76 assert(b);77 }78 return true;79}80 81int main(int, char**) {82 test();83 static_assert(test());84 85 return 0;86}87