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_BERNOULLI_DISTRIBUTION_H
 10#define _LIBCPP___RANDOM_BERNOULLI_DISTRIBUTION_H
 11
 12#include <__config>
 13#include <__random/is_valid.h>
 14#include <__random/uniform_real_distribution.h>
 15#include <iosfwd>
 16
 17#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 18#  pragma GCC system_header
 19#endif
 20
 21_LIBCPP_PUSH_MACROS
 22#include <__undef_macros>
 23
 24_LIBCPP_BEGIN_NAMESPACE_STD
 25
 26class bernoulli_distribution {
 27public:
 28  // types
 29  typedef bool result_type;
 30
 31  class param_type {
 32    double __p_;
 33
 34  public:
 35    typedef bernoulli_distribution distribution_type;
 36
 37    _LIBCPP_HIDE_FROM_ABI explicit param_type(double __p = 0.5) : __p_(__p) {}
 38
 39    _LIBCPP_HIDE_FROM_ABI double p() const { return __p_; }
 40
 41    friend _LIBCPP_HIDE_FROM_ABI bool operator==(const param_type& __x, const param_type& __y) {
 42      return __x.__p_ == __y.__p_;
 43    }
 44    friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const param_type& __x, const param_type& __y) { return !(__x == __y); }
 45  };
 46
 47private:
 48  param_type __p_;
 49
 50public:
 51  // constructors and reset functions
 52#ifndef _LIBCPP_CXX03_LANG
 53  _LIBCPP_HIDE_FROM_ABI bernoulli_distribution() : bernoulli_distribution(0.5) {}
 54  _LIBCPP_HIDE_FROM_ABI explicit bernoulli_distribution(double __p) : __p_(param_type(__p)) {}
 55#else
 56  _LIBCPP_HIDE_FROM_ABI explicit bernoulli_distribution(double __p = 0.5) : __p_(param_type(__p)) {}
 57#endif
 58  _LIBCPP_HIDE_FROM_ABI explicit bernoulli_distribution(const param_type& __p) : __p_(__p) {}
 59  _LIBCPP_HIDE_FROM_ABI void reset() {}
 60
 61  // generating functions
 62  template <class _URNG>
 63  _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g) {
 64    return (*this)(__g, __p_);
 65  }
 66  template <class _URNG>
 67  _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g, const param_type& __p);
 68
 69  // property functions
 70  _LIBCPP_HIDE_FROM_ABI double p() const { return __p_.p(); }
 71
 72  _LIBCPP_HIDE_FROM_ABI param_type param() const { return __p_; }
 73  _LIBCPP_HIDE_FROM_ABI void param(const param_type& __p) { __p_ = __p; }
 74
 75  _LIBCPP_HIDE_FROM_ABI result_type min() const { return false; }
 76  _LIBCPP_HIDE_FROM_ABI result_type max() const { return true; }
 77
 78  friend _LIBCPP_HIDE_FROM_ABI bool operator==(const bernoulli_distribution& __x, const bernoulli_distribution& __y) {
 79    return __x.__p_ == __y.__p_;
 80  }
 81  friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const bernoulli_distribution& __x, const bernoulli_distribution& __y) {
 82    return !(__x == __y);
 83  }
 84};
 85
 86template <class _URNG>
 87inline bernoulli_distribution::result_type bernoulli_distribution::operator()(_URNG& __g, const param_type& __p) {
 88  static_assert(__libcpp_random_is_valid_urng<_URNG>::value, "");
 89  uniform_real_distribution<double> __gen;
 90  return __gen(__g) < __p.p();
 91}
 92
 93template <class _CharT, class _Traits>
 94_LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>&
 95operator<<(basic_ostream<_CharT, _Traits>& __os, const bernoulli_distribution& __x) {
 96  __save_flags<_CharT, _Traits> __lx(__os);
 97  typedef basic_ostream<_CharT, _Traits> _OStream;
 98  __os.flags(_OStream::dec | _OStream::left | _OStream::fixed | _OStream::scientific);
 99  _CharT __sp = __os.widen(' ');
100  __os.fill(__sp);
101  return __os << __x.p();
102}
103
104template <class _CharT, class _Traits>
105_LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>&
106operator>>(basic_istream<_CharT, _Traits>& __is, bernoulli_distribution& __x) {
107  typedef bernoulli_distribution _Eng;
108  typedef typename _Eng::param_type param_type;
109  __save_flags<_CharT, _Traits> __lx(__is);
110  typedef basic_istream<_CharT, _Traits> _Istream;
111  __is.flags(_Istream::dec | _Istream::skipws);
112  double __p;
113  __is >> __p;
114  if (!__is.fail())
115    __x.param(param_type(__p));
116  return __is;
117}
118
119_LIBCPP_END_NAMESPACE_STD
120
121_LIBCPP_POP_MACROS
122
123#endif // _LIBCPP___RANDOM_BERNOULLI_DISTRIBUTION_H