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std::linear_congruential_engine< _UIntType, __a, __c, __m > Class Template Reference
Numerics » Random Number Generation » Random Number Generators

Public Types

typedef _UIntType result_type
 

Public Member Functions

 linear_congruential_engine (result_type __s=default_seed)
 
template<typename _Sseq , typename = typename std::enable_if<!std::is_same<_Sseq, linear_congruential_engine>::value> ::type>
 linear_congruential_engine (_Sseq &__q)
 
void discard (unsigned long long __z)
 
result_type operator() ()
 
void seed (result_type __s=default_seed)
 
template<typename _Sseq >
std::enable_if< std::is_class< _Sseq >::value >::type seed (_Sseq &__q)
 

Static Public Member Functions

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

Static Public Attributes

static constexpr result_type default_seed
 
static constexpr result_type increment
 
static constexpr result_type modulus
 
static constexpr result_type multiplier
 

Friends

template<typename _UIntType1 , _UIntType1 __a1, _UIntType1 __c1, _UIntType1 __m1, typename _CharT , typename _Traits >
std::basic_ostream< _CharT, _Traits > & operator<< (std::basic_ostream< _CharT, _Traits > &__os, const std::linear_congruential_engine< _UIntType1, __a1, __c1, __m1 > &__lcr)
 
bool operator== (const linear_congruential_engine &__lhs, const linear_congruential_engine &__rhs)
 
template<typename _UIntType1 , _UIntType1 __a1, _UIntType1 __c1, _UIntType1 __m1, typename _CharT , typename _Traits >
std::basic_istream< _CharT, _Traits > & operator>> (std::basic_istream< _CharT, _Traits > &__is, std::linear_congruential_engine< _UIntType1, __a1, __c1, __m1 > &__lcr)
 

Detailed Description

template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
class std::linear_congruential_engine< _UIntType, __a, __c, __m >

A model of a linear congruential random number generator.

A random number generator that produces pseudorandom numbers via linear function:

\[ x_{i+1}\leftarrow(ax_{i} + c) \bmod m \]

The template parameter _UIntType must be an unsigned integral type large enough to store values up to (__m-1). If the template parameter __m is 0, the modulus __m used is std::numeric_limits<_UIntType>::max() plus 1. Otherwise, the template parameters __a and __c must be less than __m.

The size of the state is $1$.

Definition at line 236 of file random.h.

Member Typedef Documentation

template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
typedef _UIntType std::linear_congruential_engine< _UIntType, __a, __c, __m >::result_type

The type of the generated random value.

Definition at line 239 of file random.h.

Constructor & Destructor Documentation

template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
std::linear_congruential_engine< _UIntType, __a, __c, __m >::linear_congruential_engine ( result_type  __s = default_seed)
inlineexplicit

Constructs a linear_congruential_engine random number generator engine with seed __s. The default seed value is 1.

Parameters
__sThe initial seed value.

Definition at line 263 of file random.h.

template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
template<typename _Sseq , typename = typename std::enable_if<!std::is_same<_Sseq, linear_congruential_engine>::value> ::type>
std::linear_congruential_engine< _UIntType, __a, __c, __m >::linear_congruential_engine ( _Sseq &  __q)
inlineexplicit

Constructs a linear_congruential_engine random number generator engine seeded from the seed sequence __q.

Parameters
__qthe seed sequence.

Definition at line 276 of file random.h.

Member Function Documentation

template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
void std::linear_congruential_engine< _UIntType, __a, __c, __m >::discard ( unsigned long long  __z)
inline

Discard a sequence of random numbers.

Definition at line 320 of file random.h.

template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
static constexpr result_type std::linear_congruential_engine< _UIntType, __a, __c, __m >::max ( )
inlinestatic

Gets the largest possible value in the output range.

Definition at line 313 of file random.h.

template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
static constexpr result_type std::linear_congruential_engine< _UIntType, __a, __c, __m >::min ( )
inlinestatic

Gets the smallest possible value in the output range.

The minimum depends on the __c parameter: if it is zero, the minimum generated must be > 0, otherwise 0 is allowed.

Definition at line 306 of file random.h.

template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
result_type std::linear_congruential_engine< _UIntType, __a, __c, __m >::operator() ( )
inline

Gets the next random number in the sequence.

Definition at line 330 of file random.h.

template<typename _UIntType , _UIntType __a, _UIntType __c, _UIntType __m>
void std::linear_congruential_engine< _UIntType, __a, __c, __m >::seed ( result_type  __s = default_seed)

Reseeds the linear_congruential_engine random number generator engine sequence to the seed __s.

Parameters
__sThe new seed.

Seeds the LCR with integral value __s, adjusted so that the ring identity is never a member of the convergence set.

Definition at line 120 of file bits/random.tcc.

template<typename _UIntType , _UIntType __a, _UIntType __c, _UIntType __m>
template<typename _Sseq >
std::enable_if< std::is_class< _Sseq >::value >::type std::linear_congruential_engine< _UIntType, __a, __c, __m >::seed ( _Sseq &  __q)

Reseeds the linear_congruential_engine random number generator engine sequence using values from the seed sequence __q.

Parameters
__qthe seed sequence.

Seeds the LCR engine with a value generated by __q.

Definition at line 136 of file bits/random.tcc.

References std::__lg(), std::dec(), std::fixed(), std::ios_base::flags(), std::left(), and std::__detail::operator>>().

Friends And Related Function Documentation

template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
template<typename _UIntType1 , _UIntType1 __a1, _UIntType1 __c1, _UIntType1 __m1, typename _CharT , typename _Traits >
std::basic_ostream<_CharT, _Traits>& operator<< ( std::basic_ostream< _CharT, _Traits > &  __os,
const std::linear_congruential_engine< _UIntType1, __a1, __c1, __m1 > &  __lcr 
)
friend

Writes the textual representation of the state x(i) of x to __os.

Parameters
__osThe output stream.
__lcrA % linear_congruential_engine random number generator.
Returns
__os.
template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
bool operator== ( const linear_congruential_engine< _UIntType, __a, __c, __m > &  __lhs,
const linear_congruential_engine< _UIntType, __a, __c, __m > &  __rhs 
)
friend

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

Parameters
__lhsA linear congruential random number generator object.
__rhsAnother linear congruential random number generator object.
Returns
true if the infinite sequences of generated values would be equal, false otherwise.

Definition at line 348 of file random.h.

template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
template<typename _UIntType1 , _UIntType1 __a1, _UIntType1 __c1, _UIntType1 __m1, typename _CharT , typename _Traits >
std::basic_istream<_CharT, _Traits>& operator>> ( std::basic_istream< _CharT, _Traits > &  __is,
std::linear_congruential_engine< _UIntType1, __a1, __c1, __m1 > &  __lcr 
)
friend

Sets the state of the engine by reading its textual representation from __is.

The textual representation must have been previously written using an output stream whose imbued locale and whose type's template specialization arguments _CharT and _Traits were the same as those of __is.

Parameters
__isThe input stream.
__lcrA % linear_congruential_engine random number generator.
Returns
__is.

Member Data Documentation

template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
constexpr _UIntType std::linear_congruential_engine< _UIntType, __a, __c, __m >::increment
static

An increment.

Definition at line 250 of file random.h.

template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
constexpr _UIntType std::linear_congruential_engine< _UIntType, __a, __c, __m >::modulus
static

The modulus.

Definition at line 252 of file random.h.

template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
constexpr _UIntType std::linear_congruential_engine< _UIntType, __a, __c, __m >::multiplier
static

The multiplier.

Definition at line 248 of file random.h.

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