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 sentinel_t<Base> base() const;
12
13 #include <cassert>
14 #include <ranges>
15 #include <tuple>
16 #include <type_traits>
17 #include <utility>
18
19 struct Sent {
20 int i;
21
operator ==(std::tuple<int> *,const Sent &)22 friend constexpr bool operator==(std::tuple<int>*, const Sent&) { return true; }
23 };
24
test()25 constexpr bool test() {
26 using BaseRange = std::ranges::subrange<std::tuple<int>*, Sent>;
27 using EleRange = std::ranges::elements_view<BaseRange, 0>;
28 using EleSent = std::ranges::sentinel_t<EleRange>;
29
30 const EleSent st{Sent{5}};
31 std::same_as<Sent> decltype(auto) base = st.base();
32 assert(base.i == 5);
33
34 return true;
35 }
36
main(int,char **)37 int main(int, char**) {
38 test();
39 static_assert(test());
40 return 0;
41 }
42