chromium/third_party/libc++/src/include/__algorithm/uniform_random_bit_generator_adaptor.h

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP___ALGORITHM_RANGES_UNIFORM_RANDOM_BIT_GENERATOR_ADAPTOR_H
#define _LIBCPP___ALGORITHM_RANGES_UNIFORM_RANDOM_BIT_GENERATOR_ADAPTOR_H

#include <__config>
#include <__functional/invoke.h>
#include <__type_traits/remove_cvref.h>

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#  pragma GCC system_header
#endif

#if _LIBCPP_STD_VER >= 20

_LIBCPP_PUSH_MACROS
#  include <__undef_macros>

_LIBCPP_BEGIN_NAMESPACE_STD

// Range versions of random algorithms (e.g. `std::shuffle`) are less constrained than their classic counterparts.
// Range algorithms only require the given generator to satisfy the `std::uniform_random_bit_generator` concept.
// Classic algorithms require the given generator to meet the uniform random bit generator requirements; these
// requirements include satisfying `std::uniform_random_bit_generator` and add a requirement for the generator to
// provide a nested `result_type` typedef (see `[rand.req.urng]`).
//
// To be able to reuse classic implementations, make the given generator meet the classic requirements by wrapping
// it into an adaptor type that forwards all of its interface and adds the required typedef.
template <class _Gen>
class _ClassicGenAdaptor { … };

_LIBCPP_END_NAMESPACE_STD

_LIBCPP_POP_MACROS

#endif // _LIBCPP_STD_VER >= 20

#endif // _LIBCPP___ALGORITHM_RANGES_UNIFORM_RANDOM_BIT_GENERATOR_ADAPTOR_H