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-has-no-incomplete-ranges
11 
12 // template<class R>
13 // concept __nothrow_forward_range;
14 
15 #include <memory>
16 
17 #include "test_iterators.h"
18 #include "test_range.h"
19 
20 // Has to be a template to work with `test_range`.
21 template <typename>
22 struct ForwardProxyIterator {
23   using value_type = int;
24   using difference_type = int;
25   ForwardProxyIterator& operator++();
26   ForwardProxyIterator operator++(int);
27   bool operator==(const ForwardProxyIterator&) const;
28 
29   int operator*() const;
30 };
31 
32 static_assert(std::ranges::__nothrow_forward_range<test_range<forward_iterator>>);
33 static_assert(!std::ranges::__nothrow_forward_range<test_range<cpp20_input_iterator>>);
34 static_assert(std::ranges::forward_range<test_range<ForwardProxyIterator>>);
35 static_assert(!std::ranges::__nothrow_forward_range<test_range<ForwardProxyIterator>>);
36 
forward_subsumes_input(std::ranges::__nothrow_forward_range auto &&)37 constexpr bool forward_subsumes_input(std::ranges::__nothrow_forward_range auto&&) {
38   return true;
39 }
40 constexpr bool forward_subsumes_input(std::ranges::__nothrow_input_range auto&&);
41 
42 static_assert(forward_subsumes_input("foo"));
43