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 // UNSUPPORTED: libcpp-no-concepts
11 // UNSUPPORTED: gcc-10
12 // UNSUPPORTED: libcpp-has-no-incomplete-ranges
13 
14 // std::ranges::borrowed_subrange_t;
15 
16 #include <ranges>
17 
18 #include <concepts>
19 #include <span>
20 #include <string>
21 #include <string_view>
22 #include <vector>
23 
24 static_assert(std::same_as<std::ranges::borrowed_subrange_t<std::string>, std::ranges::dangling>);
25 static_assert(std::same_as<std::ranges::borrowed_subrange_t<std::string&&>, std::ranges::dangling>);
26 static_assert(std::same_as<std::ranges::borrowed_subrange_t<std::vector<int> >, std::ranges::dangling>);
27 
28 static_assert(
29     std::same_as<std::ranges::borrowed_subrange_t<std::string&>, std::ranges::subrange<std::string::iterator> >);
30 
31 static_assert(
32     std::same_as<std::ranges::borrowed_subrange_t<std::span<int> >, std::ranges::subrange<std::span<int>::iterator> >);
33 
34 static_assert(std::same_as<std::ranges::borrowed_subrange_t<std::string_view>,
35                            std::ranges::subrange<std::string_view::iterator> >);
36 
37 template <class T>
38 constexpr bool has_type = requires {
39   typename std::ranges::borrowed_subrange_t<T>;
40 };
41 
42 static_assert(!has_type<int>);
43 
44 struct S {};
45 static_assert(!has_type<S>);
46