libcxx/include/__random/uniform_random_bit_generator.h

   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