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 
13 // template<class R>
14 // concept bidirectional_range;
15 
16 #include <ranges>
17 
18 #include "test_range.h"
19 
20 namespace stdr = std::ranges;
21 
22 template <template <class...> class I>
23 constexpr bool check_bidirectional_range() {
24   constexpr bool result = stdr::bidirectional_range<test_range<I> >;
25   static_assert(stdr::bidirectional_range<test_range<I> const> == result);
26   static_assert(stdr::bidirectional_range<test_non_const_common_range<I> > == result);
27   static_assert(stdr::bidirectional_range<test_non_const_range<I> > == result);
28   static_assert(stdr::bidirectional_range<test_common_range<I> > == result);
29   static_assert(stdr::bidirectional_range<test_common_range<I> const> == result);
30   static_assert(!stdr::bidirectional_range<test_non_const_common_range<I> const>);
31   static_assert(!stdr::bidirectional_range<test_non_const_range<I> const>);
32   return result;
33 }
34 
35 static_assert(!check_bidirectional_range<cpp17_input_iterator>());
36 static_assert(!check_bidirectional_range<cpp20_input_iterator>());
37 static_assert(!check_bidirectional_range<forward_iterator>());
38 static_assert(check_bidirectional_range<bidirectional_iterator>());
39 static_assert(check_bidirectional_range<random_access_iterator>());
40 static_assert(check_bidirectional_range<contiguous_iterator>());
41