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// template<class R>
12// concept forward_range;
13
14#include <ranges>
15
16#include "test_iterators.h"
17#include "test_range.h"
18
19template <template <class...> class I>
20constexpr bool check_forward_range() {
21 constexpr bool result = std::ranges::forward_range<test_range<I> >;
22 static_assert(std::ranges::forward_range<test_range<I> const> == result);
23 static_assert(std::ranges::forward_range<test_non_const_common_range<I> > == result);
24 static_assert(std::ranges::forward_range<test_non_const_range<I> > == result);
25 static_assert(std::ranges::forward_range<test_common_range<I> > == result);
26 static_assert(std::ranges::forward_range<test_common_range<I> const> == result);
27 static_assert(!std::ranges::forward_range<test_non_const_common_range<I> const>);
28 static_assert(!std::ranges::forward_range<test_non_const_range<I> const>);
29 return result;
30}
31
32static_assert(!check_forward_range<cpp17_input_iterator>());
33static_assert(!check_forward_range<cpp20_input_iterator>());
34static_assert(check_forward_range<forward_iterator>());
35static_assert(check_forward_range<bidirectional_iterator>());
36static_assert(check_forward_range<random_access_iterator>());
37static_assert(check_forward_range<contiguous_iterator>());
38
39// Test ADL-proofing.
40struct Incomplete;
41template<class T> struct Holder { T t; };
42
43static_assert(!std::ranges::forward_range<Holder<Incomplete>*>);
44static_assert(!std::ranges::forward_range<Holder<Incomplete>*&>);
45static_assert(!std::ranges::forward_range<Holder<Incomplete>*&&>);
46static_assert(!std::ranges::forward_range<Holder<Incomplete>* const>);
47static_assert(!std::ranges::forward_range<Holder<Incomplete>* const&>);
48static_assert(!std::ranges::forward_range<Holder<Incomplete>* const&&>);
49
50static_assert( std::ranges::forward_range<Holder<Incomplete>*[10]>);
51static_assert( std::ranges::forward_range<Holder<Incomplete>*(&)[10]>);
52static_assert( std::ranges::forward_range<Holder<Incomplete>*(&&)[10]>);
53static_assert( std::ranges::forward_range<Holder<Incomplete>* const[10]>);
54static_assert( std::ranges::forward_range<Holder<Incomplete>* const(&)[10]>);
55static_assert( std::ranges::forward_range<Holder<Incomplete>* const(&&)[10]>);
56

source code of libcxx/test/std/ranges/range.req/range.refinements/forward_range.compile.pass.cpp