1d8fad661SChristopher Di Bella //===----------------------------------------------------------------------===//
2d8fad661SChristopher Di Bella //
3d8fad661SChristopher Di Bella // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4d8fad661SChristopher Di Bella // See https://llvm.org/LICENSE.txt for license information.
5d8fad661SChristopher Di Bella // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6d8fad661SChristopher Di Bella //
7d8fad661SChristopher Di Bella //===----------------------------------------------------------------------===//
8d8fad661SChristopher Di Bella 
9d8fad661SChristopher Di Bella // UNSUPPORTED: c++03, c++11, c++14, c++17
10d8fad661SChristopher Di Bella 
11d8fad661SChristopher Di Bella // template<class T>
12d8fad661SChristopher Di Bella // concept input_iterator;
13d8fad661SChristopher Di Bella 
14d8fad661SChristopher Di Bella // std::ranges::forward_range
15d8fad661SChristopher Di Bella 
16d8fad661SChristopher Di Bella #include <ranges>
17d8fad661SChristopher Di Bella 
18d8fad661SChristopher Di Bella #include <iterator>
19d8fad661SChristopher Di Bella 
20d8fad661SChristopher Di Bella struct range {
21d8fad661SChristopher Di Bella   int* begin();
22d8fad661SChristopher Di Bella   int* end();
23d8fad661SChristopher Di Bella };
24d8fad661SChristopher Di Bella 
25d8fad661SChristopher Di Bella template<std::ranges::range R>
26d8fad661SChristopher Di Bella requires std::input_iterator<std::ranges::iterator_t<R>>
check_input_range_subsumption()27*88b73a98SLouis Dionne constexpr bool check_input_range_subsumption() {
28d8fad661SChristopher Di Bella   return false;
29d8fad661SChristopher Di Bella }
30d8fad661SChristopher Di Bella 
31d8fad661SChristopher Di Bella template<std::ranges::input_range>
32d8fad661SChristopher Di Bella requires true
check_input_range_subsumption()33*88b73a98SLouis Dionne constexpr bool check_input_range_subsumption() {
34d8fad661SChristopher Di Bella   return true;
35d8fad661SChristopher Di Bella }
36d8fad661SChristopher Di Bella 
37d8fad661SChristopher Di Bella static_assert(check_input_range_subsumption<range>());
38d8fad661SChristopher Di Bella 
39d8fad661SChristopher Di Bella template<std::ranges::input_range R>
40d8fad661SChristopher Di Bella requires std::forward_iterator<std::ranges::iterator_t<R>>
check_forward_range_subsumption()41*88b73a98SLouis Dionne constexpr bool check_forward_range_subsumption() {
42d8fad661SChristopher Di Bella   return false;
43d8fad661SChristopher Di Bella }
44d8fad661SChristopher Di Bella 
45d8fad661SChristopher Di Bella template<std::ranges::forward_range>
46d8fad661SChristopher Di Bella requires true
check_forward_range_subsumption()47*88b73a98SLouis Dionne constexpr bool check_forward_range_subsumption() {
48d8fad661SChristopher Di Bella   return true;
49d8fad661SChristopher Di Bella }
50d8fad661SChristopher Di Bella 
51d8fad661SChristopher Di Bella static_assert(check_forward_range_subsumption<range>());
52d8fad661SChristopher Di Bella 
53d8fad661SChristopher Di Bella template<std::ranges::forward_range R>
54d8fad661SChristopher Di Bella requires std::bidirectional_iterator<std::ranges::iterator_t<R>>
check_bidirectional_range_subsumption()55*88b73a98SLouis Dionne constexpr bool check_bidirectional_range_subsumption() {
56d8fad661SChristopher Di Bella   return false;
57d8fad661SChristopher Di Bella }
58d8fad661SChristopher Di Bella 
59d8fad661SChristopher Di Bella template<std::ranges::bidirectional_range>
60d8fad661SChristopher Di Bella requires true
check_bidirectional_range_subsumption()61*88b73a98SLouis Dionne constexpr bool check_bidirectional_range_subsumption() {
62d8fad661SChristopher Di Bella   return true;
63d8fad661SChristopher Di Bella }
64d8fad661SChristopher Di Bella 
65d8fad661SChristopher Di Bella static_assert(check_bidirectional_range_subsumption<range>());
66d8fad661SChristopher Di Bella 
67d8fad661SChristopher Di Bella template<std::ranges::bidirectional_range R>
68d8fad661SChristopher Di Bella requires std::random_access_iterator<std::ranges::iterator_t<R>>
check_random_access_range_subsumption()69d8fad661SChristopher Di Bella constexpr bool check_random_access_range_subsumption() {
70d8fad661SChristopher Di Bella   return false;
71d8fad661SChristopher Di Bella }
72d8fad661SChristopher Di Bella 
73d8fad661SChristopher Di Bella template<std::ranges::random_access_range>
74d8fad661SChristopher Di Bella requires true
check_random_access_range_subsumption()75d8fad661SChristopher Di Bella constexpr bool check_random_access_range_subsumption() {
76d8fad661SChristopher Di Bella   return true;
77d8fad661SChristopher Di Bella }
78d8fad661SChristopher Di Bella 
79d8fad661SChristopher Di Bella static_assert(check_random_access_range_subsumption<range>());
8034503987Szoecarver 
8134503987Szoecarver template<std::ranges::random_access_range R>
8234503987Szoecarver requires std::random_access_iterator<std::ranges::iterator_t<R>>
check_contiguous_range_subsumption()8334503987Szoecarver constexpr bool check_contiguous_range_subsumption() {
8434503987Szoecarver   return false;
8534503987Szoecarver }
8634503987Szoecarver 
8734503987Szoecarver template<std::ranges::contiguous_range>
8834503987Szoecarver requires true
check_contiguous_range_subsumption()8934503987Szoecarver constexpr bool check_contiguous_range_subsumption() {
9034503987Szoecarver   return true;
9134503987Szoecarver }
9234503987Szoecarver 
9334503987Szoecarver static_assert(check_contiguous_range_subsumption<range>());
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