std::discard_block_engine< _RandomNumberEngine, __p, __r > Class Template Reference
Numerics » Random Number Generation » Random Number Generators

## Public Types

typedef _RandomNumberEngine::result_type | result_type

## Public Member Functions

| discard_block_engine ()
| discard_block_engine (const _RandomNumberEngine &__rng)
| discard_block_engine (_RandomNumberEngine &&__rng)
| discard_block_engine (result_type __s)
template<typename _Sseq , typename = typename std::enable_if<!std::is_same<_Sseq, discard_block_engine>::value && !std::is_same<_Sseq, _RandomNumberEngine>::value> ::type>
| discard_block_engine (_Sseq &__q)
const _RandomNumberEngine & | base () const noexcept
void | discard (unsigned long long __z)
result_type | operator() ()
void | seed ()
void | seed (result_type __s)
template<typename _Sseq >
void | seed (_Sseq &__q)

## Static Public Member Functions

static constexpr result_type | max ()
static constexpr result_type | min ()

## Static Public Attributes

static constexpr size_t | block_size
static constexpr size_t | used_block

## Friends

template<typename _RandomNumberEngine1 , size_t __p1, size_t __r1, typename _CharT , typename _Traits >
std::basic_ostream< _CharT, _Traits > & | operator<< (std::basic_ostream< _CharT, _Traits > &__os, const std::discard_block_engine< _RandomNumberEngine1, __p1, __r1 > &__x)
bool | operator== (const discard_block_engine &__lhs, const discard_block_engine &__rhs)
template<typename _RandomNumberEngine1 , size_t __p1, size_t __r1, typename _CharT , typename _Traits >
std::basic_istream< _CharT, _Traits > & | operator>> (std::basic_istream< _CharT, _Traits > &__is, std::discard_block_engine< _RandomNumberEngine1, __p1, __r1 > &__x)

## Detailed Description

### template<typename _RandomNumberEngine, size_t __p, size_t __r>
class std::discard_block_engine< _RandomNumberEngine, __p, __r >

Produces random numbers from some base engine by discarding blocks of data.

0 <= `__r` <= `__p`

Definition at line 839 of file random.h.

## Member Typedef Documentation

## result_type

template<typename _RandomNumberEngine, size_t __p, size_t __r>

typedef _RandomNumberEngine::result_type std::discard_block_engine< _RandomNumberEngine, __p, __r >::result_type

The type of the generated random value.

Definition at line 842 of file random.h.

## Constructor & Destructor Documentation

## discard_block_engine() [1/5]

template<typename _RandomNumberEngine, size_t __p, size_t __r>

std::discard_block_engine< _RandomNumberEngine, __p, __r >::discard_block_engine | ( |  | ) |

inline

Constructs a default discard_block_engine engine.

The underlying engine is default constructed as well.

Definition at line 857 of file random.h.

## discard_block_engine() [2/5]

template<typename _RandomNumberEngine, size_t __p, size_t __r>

std::discard_block_engine< _RandomNumberEngine, __p, __r >::discard_block_engine | ( | const _RandomNumberEngine & | __rng | ) |

inline explicit

Copy constructs a discard_block_engine engine.

Copies an existing base class random number generator.

Parameters

  __rng | An existing (base class) engine object.

Definition at line 867 of file random.h.

## discard_block_engine() [3/5]

template<typename _RandomNumberEngine, size_t __p, size_t __r>

std::discard_block_engine< _RandomNumberEngine, __p, __r >::discard_block_engine | ( | _RandomNumberEngine && | __rng | ) |

inline explicit

Move constructs a discard_block_engine engine.

Copies an existing base class random number generator.

Parameters

  __rng | An existing (base class) engine object.

Definition at line 877 of file random.h.

## discard_block_engine() [4/5]

template<typename _RandomNumberEngine, size_t __p, size_t __r>

std::discard_block_engine< _RandomNumberEngine, __p, __r >::discard_block_engine | ( | result_type | __s | ) |

inline explicit

Seed constructs a discard_block_engine engine.

Constructs the underlying generator engine seeded with `__s`.

Parameters

  __s | A seed value for the base class engine.

Definition at line 887 of file random.h.

## discard_block_engine() [5/5]

template<typename _RandomNumberEngine, size_t __p, size_t __r>
template<typename _Sseq , typename = typename std::enable_if<!std::is_same<_Sseq, discard_block_engine>::value && !std::is_same<_Sseq, _RandomNumberEngine>::value> ::type>

std::discard_block_engine< _RandomNumberEngine, __p, __r >::discard_block_engine | ( | _Sseq & | __q | ) |

inline explicit

Generator construct a discard_block_engine engine.

Parameters

  __q | A seed sequence.

Definition at line 900 of file random.h.

## Member Function Documentation

## base()

template<typename _RandomNumberEngine, size_t __p, size_t __r>

const _RandomNumberEngine& std::discard_block_engine< _RandomNumberEngine, __p, __r >::base | ( |  | ) | const

inline noexcept

Gets a const reference to the underlying generator engine object.

Definition at line 944 of file random.h.

Referenced by std::shuffle_order_engine< _RandomNumberEngine, __k >::operator()().

## discard()

template<typename _RandomNumberEngine, size_t __p, size_t __r>

void std::discard_block_engine< _RandomNumberEngine, __p, __r >::discard | ( | unsigned long long | __z | ) |

inline

Discard a sequence of random numbers.

Definition at line 965 of file random.h.

## max()

template<typename _RandomNumberEngine, size_t __p, size_t __r>

static constexpr result_type std::discard_block_engine< _RandomNumberEngine, __p, __r >::max | ( |  | ) |

inline static

Gets the maximum value in the generated random number range.

Definition at line 958 of file random.h.

References std::max().

## min()

template<typename _RandomNumberEngine, size_t __p, size_t __r>

static constexpr result_type std::discard_block_engine< _RandomNumberEngine, __p, __r >::min | ( |  | ) |

inline static

Gets the minimum value in the generated random number range.

Definition at line 951 of file random.h.

References std::min().

## operator()()

template<typename _RandomNumberEngine , size_t __p, size_t __r>

discard_block_engine< _RandomNumberEngine, __p, __r >::result_type std::discard_block_engine< _RandomNumberEngine, __p, __r >::operator() | ( |  | ) |

Gets the next value in the generated random number sequence.

Definition at line 685 of file bits/random.tcc.

References std::dec(), std::fixed(), std::ios_base::flags(), std::left(), std::independent_bits_engine< _RandomNumberEngine, __w, _UIntType >::operator()(), std::__detail::operator>>(), and std::skipws().

Referenced by std::subtract_with_carry_engine< _UIntType, __w, __s, __r >::operator()().

## seed() [1/3]

template<typename _RandomNumberEngine, size_t __p, size_t __r>

void std::discard_block_engine< _RandomNumberEngine, __p, __r >::seed | ( |  | ) |

inline

Reseeds the discard_block_engine object with the default seed for the underlying base class generator engine.

Definition at line 909 of file random.h.

## seed() [2/3]

template<typename _RandomNumberEngine, size_t __p, size_t __r>

void std::discard_block_engine< _RandomNumberEngine, __p, __r >::seed | ( | result_type | __s | ) |

inline

Reseeds the discard_block_engine object with the default seed for the underlying base class generator engine.

Definition at line 920 of file random.h.

## seed() [3/3]

template<typename _RandomNumberEngine, size_t __p, size_t __r>
template<typename _Sseq >

void std::discard_block_engine< _RandomNumberEngine, __p, __r >::seed | ( | _Sseq & | __q | ) |

inline

Reseeds the discard_block_engine object with the given seed sequence.

Parameters

  __q | A seed generator function.

Definition at line 933 of file random.h.

## Friends And Related Function Documentation

## operator<<

template<typename _RandomNumberEngine, size_t __p, size_t __r>
template<typename _RandomNumberEngine1 , size_t __p1, size_t __r1, typename _CharT , typename _Traits >

std::basic_ostream<_CharT, _Traits>& operator<< | ( | std::basic_ostream< _CharT, _Traits > & | __os,
|  | const std::discard_block_engine< _RandomNumberEngine1, __p1, __r1 > & | __x
| ) |  |

friend

Inserts the current state of a discard_block_engine random number generator engine `__x` into the output stream `__os`.

Parameters

  __os | An output stream.
  __x | A discard_block_engine random number generator engine.

Returns
  The output stream with the state of `__x` inserted or in an error state.

## operator==

template<typename _RandomNumberEngine, size_t __p, size_t __r>

bool operator== | ( | const discard_block_engine< _RandomNumberEngine, __p, __r > & | __lhs,
|  | const discard_block_engine< _RandomNumberEngine, __p, __r > & | __rhs
| ) |  |

friend

Compares two discard_block_engine random number generator objects of the same type for equality.

Parameters

  __lhs | A discard_block_engine random number generator object.
  __rhs | Another discard_block_engine random number generator object.

Returns
  true if the infinite sequences of generated values would be equal, false otherwise.

Definition at line 989 of file random.h.

## operator>>

template<typename _RandomNumberEngine, size_t __p, size_t __r>
template<typename _RandomNumberEngine1 , size_t __p1, size_t __r1, typename _CharT , typename _Traits >

std::basic_istream<_CharT, _Traits>& operator>> | ( | std::basic_istream< _CharT, _Traits > & | __is,
|  | std::discard_block_engine< _RandomNumberEngine1, __p1, __r1 > & | __x
| ) |  |

friend

Extracts the current state of a % subtract_with_carry_engine random number generator engine `__x` from the input stream `__is`.

Parameters

  __is | An input stream.
  __x | A discard_block_engine random number generator engine.

Returns
  The input stream with the state of `__x` extracted or in an error state.

The documentation for this class was generated from the following files:

- random.h
- bits/random.tcc