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
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 explicit
35template <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 correctly
51 {
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 correctly
60 {
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

source code of libcxx/test/std/ranges/range.adaptors/range.take.while/sentinel/ctor.base.pass.cpp