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_GEOMETRIC_DISTRIBUTION_H
 10#define _LIBCPP___RANDOM_GEOMETRIC_DISTRIBUTION_H
 11
 12#include <__config>
 13#include <__random/is_valid.h>
 14#include <__random/negative_binomial_distribution.h>
 15#include <iosfwd>
 16#include <limits>
 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
 27template <class _IntType = int>
 28class geometric_distribution {
 29  static_assert(__libcpp_random_is_valid_inttype<_IntType>::value, "IntType must be a supported integer type");
 30
 31public:
 32  // types
 33  typedef _IntType result_type;
 34
 35  class param_type {
 36    double __p_;
 37
 38  public:
 39    typedef geometric_distribution distribution_type;
 40
 41    _LIBCPP_HIDE_FROM_ABI explicit param_type(double __p = 0.5) : __p_(__p) {}
 42
 43    _LIBCPP_HIDE_FROM_ABI double p() const { return __p_; }
 44
 45    friend _LIBCPP_HIDE_FROM_ABI bool operator==(const param_type& __x, const param_type& __y) {
 46      return __x.__p_ == __y.__p_;
 47    }
 48    friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const param_type& __x, const param_type& __y) { return !(__x == __y); }
 49  };
 50
 51private:
 52  param_type __p_;
 53
 54public:
 55  // constructors and reset functions
 56#ifndef _LIBCPP_CXX03_LANG
 57  _LIBCPP_HIDE_FROM_ABI geometric_distribution() : geometric_distribution(0.5) {}
 58  _LIBCPP_HIDE_FROM_ABI explicit geometric_distribution(double __p) : __p_(__p) {}
 59#else
 60  _LIBCPP_HIDE_FROM_ABI explicit geometric_distribution(double __p = 0.5) : __p_(__p) {}
 61#endif
 62  _LIBCPP_HIDE_FROM_ABI explicit geometric_distribution(const param_type& __p) : __p_(__p) {}
 63  _LIBCPP_HIDE_FROM_ABI void reset() {}
 64
 65  // generating functions
 66  template <class _URNG>
 67  _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g) {
 68    return (*this)(__g, __p_);
 69  }
 70  template <class _URNG>
 71  _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g, const param_type& __p) {
 72    return negative_binomial_distribution<result_type>(1, __p.p())(__g);
 73  }
 74
 75  // property functions
 76  _LIBCPP_HIDE_FROM_ABI double p() const { return __p_.p(); }
 77
 78  _LIBCPP_HIDE_FROM_ABI param_type param() const { return __p_; }
 79  _LIBCPP_HIDE_FROM_ABI void param(const param_type& __p) { __p_ = __p; }
 80
 81  _LIBCPP_HIDE_FROM_ABI result_type min() const { return 0; }
 82  _LIBCPP_HIDE_FROM_ABI result_type max() const { return numeric_limits<result_type>::max(); }
 83
 84  friend _LIBCPP_HIDE_FROM_ABI bool operator==(const geometric_distribution& __x, const geometric_distribution& __y) {
 85    return __x.__p_ == __y.__p_;
 86  }
 87  friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const geometric_distribution& __x, const geometric_distribution& __y) {
 88    return !(__x == __y);
 89  }
 90};
 91
 92template <class _CharT, class _Traits, class _IntType>
 93_LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>&
 94operator<<(basic_ostream<_CharT, _Traits>& __os, const geometric_distribution<_IntType>& __x) {
 95  __save_flags<_CharT, _Traits> __lx(__os);
 96  typedef basic_ostream<_CharT, _Traits> _OStream;
 97  __os.flags(_OStream::dec | _OStream::left | _OStream::fixed | _OStream::scientific);
 98  return __os << __x.p();
 99}
100
101template <class _CharT, class _Traits, class _IntType>
102_LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>&
103operator>>(basic_istream<_CharT, _Traits>& __is, geometric_distribution<_IntType>& __x) {
104  typedef geometric_distribution<_IntType> _Eng;
105  typedef typename _Eng::param_type param_type;
106  __save_flags<_CharT, _Traits> __lx(__is);
107  typedef basic_istream<_CharT, _Traits> _Istream;
108  __is.flags(_Istream::dec | _Istream::skipws);
109  double __p;
110  __is >> __p;
111  if (!__is.fail())
112    __x.param(param_type(__p));
113  return __is;
114}
115
116_LIBCPP_END_NAMESPACE_STD
117
118_LIBCPP_POP_MACROS
119
120#endif // _LIBCPP___RANDOM_GEOMETRIC_DISTRIBUTION_H