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 #ifndef _LIBCPP___RANDOM_UNIFORM_RANDOM_BIT_GENERATOR_H
10 #define _LIBCPP___RANDOM_UNIFORM_RANDOM_BIT_GENERATOR_H
11 
12 #include <__concepts/arithmetic.h>
13 #include <__concepts/invocable.h>
14 #include <__concepts/same_as.h>
15 #include <__config>
16 #include <__functional/invoke.h>
17 #include <__type_traits/integral_constant.h>
18 
19 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
20 #  pragma GCC system_header
21 #endif
22 
23 _LIBCPP_PUSH_MACROS
24 #include <__undef_macros>
25 
26 _LIBCPP_BEGIN_NAMESPACE_STD
27 
28 #if _LIBCPP_STD_VER >= 20
29 
30 // [rand.req.urng]
31 template<class _Gen>
32 concept uniform_random_bit_generator =
33   invocable<_Gen&> && unsigned_integral<invoke_result_t<_Gen&>> &&
34   requires {
35     { _Gen::min() } -> same_as<invoke_result_t<_Gen&>>;
36     { _Gen::max() } -> same_as<invoke_result_t<_Gen&>>;
37     requires bool_constant<(_Gen::min() < _Gen::max())>::value;
38   };
39 
40 #endif // _LIBCPP_STD_VER >= 20
41 
42 _LIBCPP_END_NAMESPACE_STD
43 
44 _LIBCPP_POP_MACROS
45 
46 #endif // _LIBCPP___RANDOM_UNIFORM_RANDOM_BIT_GENERATOR_H
47