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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-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef _LIBCPP___RANDOM_RANDOM_DEVICE_H10#define _LIBCPP___RANDOM_RANDOM_DEVICE_H11 12#include <__config>13#include <string>14 15#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)16# pragma GCC system_header17#endif18 19_LIBCPP_PUSH_MACROS20#include <__undef_macros>21 22_LIBCPP_BEGIN_NAMESPACE_STD23 24#if _LIBCPP_HAS_RANDOM_DEVICE25 26class _LIBCPP_EXPORTED_FROM_ABI random_device {27# ifdef _LIBCPP_USING_DEV_RANDOM28 int __f_;29# elif !defined(_LIBCPP_ABI_NO_RANDOM_DEVICE_COMPATIBILITY_LAYOUT)30 _LIBCPP_DIAGNOSTIC_PUSH31 _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wunused-private-field")32 33 // Apple platforms used to use the `_LIBCPP_USING_DEV_RANDOM` code path, and now34 // use `arc4random()` as of this comment. In order to avoid breaking the ABI, we35 // retain the same layout as before.36# if defined(__APPLE__)37 int __padding_; // padding to fake the `__f_` field above38# endif39 40 // ... vendors can add workarounds here if they switch to a different representation ...41 42 _LIBCPP_DIAGNOSTIC_POP43# endif44 45public:46 // types47 typedef unsigned result_type;48 49 // generator characteristics50 static _LIBCPP_CONSTEXPR const result_type _Min = 0;51 static _LIBCPP_CONSTEXPR const result_type _Max = 0xFFFFFFFFu;52 53 _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR result_type min() { return _Min; }54 _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR result_type max() { return _Max; }55 56 // constructors57# ifndef _LIBCPP_CXX03_LANG58 _LIBCPP_HIDE_FROM_ABI random_device() : random_device("/dev/urandom") {}59 explicit random_device(const string& __token);60# else61 explicit random_device(const string& __token = "/dev/urandom");62# endif63 ~random_device();64 65 // generating functions66 result_type operator()();67 68 // property functions69 double entropy() const _NOEXCEPT;70 71 random_device(const random_device&) = delete;72 void operator=(const random_device&) = delete;73};74 75#endif // _LIBCPP_HAS_RANDOM_DEVICE76 77_LIBCPP_END_NAMESPACE_STD78 79_LIBCPP_POP_MACROS80 81#endif // _LIBCPP___RANDOM_RANDOM_DEVICE_H82