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