STD::LINEAR_CONGRUENTIAL_ENGINE(3cxx)

📦
version 14-20240412 · 19 versions
, in ubuntu noble

✨ NAME ✨

okay bestie, this is the 3cxx manual page for std::linear_congruential_engine< _UIntType, __a, __c, __m > — and it is literally a model of a linear congruential random number generator. no cap. 💖

🌈 SYNOPSIS 🌈

#include <random>

🎀 Public Types 🎀

  • typedef _UIntType result_type — the type it spits out, periodt.

💅 Public Member Functions 💅

  • linear_congruential_engine () — Constructs a linear_congruential_engine random number generator engine with seed 1.
  • template<typename _Sseq , typename = _If_seed_seq<_Sseq>> linear_congruential_engine (_Sseq &__q) — Constructs a linear_congruential_engine random number generator engine seeded from the seed sequence __q.
  • linear_congruential_engine (result_type __s) — Constructs a linear_congruential_engine random number generator engine with seed __s. The default seed value is 1.
  • void discard (unsigned long long __z) — Discard a sequence of random numbers.
  • result_type operator() () — Gets the next random number in the sequence.
  • template<typename _Sseq > _If_seed_seq< _Sseq > seed (_Sseq &__q) — Reseeds the linear_congruential_engine random number generator engine sequence using values from the seed sequence __q.
  • template<typename _Sseq > auto seed (_Sseq &__q) -> _If_seed_seq< _Sseq > — another seed-sequence overload, slay.
  • void seed (result_type __s=default_seed) — Reseeds the linear_congruential_engine random number generator engine sequence to the seed __s.

✨ Static Public Member Functions ✨

  • static constexpr result_type max () — Gets the largest possible value in the output range.
  • static constexpr result_type min () — Gets the smallest possible value in the output range.

🦋 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) — Writes the textual representation of the state x(i) of x to __os.
  • bool operator== (const linear_congruential_engine &__lhs, const linear_congruential_engine &__rhs) — Compares two linear congruential random number generator objects of the same type for equality.
  • 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) — Sets the state of the engine by reading its textual representation from __is.

🌸 Detailed Description 🌸

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

The self-description starts like this, quote mark and all: "A model of a linear congruential random number generator.

It's a random number generator that produces pseudorandom numbers via linear function. The manpage renders the formula like this, weird artifacts and all — I'm keeping it exactly as written, bestie:

                     o
x_{i+1}tarrow(ax_{i} + c) d ]

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 $1$ — yes, the dollar signs are literally in the text, iykyk. 💅

Since: C++11

👑 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. iconic. ✨

🍓 Constructor & Destructor Documentation 🍓

template<typename _UIntType , _UIntType __a, _UIntType __c, _UIntType __m>
std::linear_congruential_engine< _UIntType, __a, __c, __m >::linear_congruential_engine () [inline]

Constructs a linear_congruential_engine random number generator engine with seed 1.

template<typename _UIntType , _UIntType __a, _UIntType __c, _UIntType __m>
std::linear_congruential_engine< _UIntType, __a, __c, __m >::linear_congruential_engine (result_type __s) [inline], [explicit]

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

  • Parameters:
    • __s — The initial seed value.
  • References: std::linear_congruential_engine< _UIntType, __a, __c, __m >::seed().
template<typename _UIntType , _UIntType __a, _UIntType __c, _UIntType __m>
template<typename _Sseq , typename  = _If_seed_seq<_Sseq>>
std::linear_congruential_engine< _UIntType, __a, __c, __m >::linear_congruential_engine (_Sseq & __q) [inline], [explicit]

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

  • Parameters:
    • __q — the seed sequence.
  • References: std::linear_congruential_engine< _UIntType, __a, __c, __m >::seed().

🔥 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. bye-bye, numbers. 👋

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

Gets the largest possible value in the output range.

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

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. important little detail, don't skip it. 🫶

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.

template<typename _UIntType , _UIntType __a, _UIntType __c, _UIntType __m>
template<typename _Sseq > _If_seed_seq< _Sseq >
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:
    • __q — the seed sequence.
template<typename _UIntType , _UIntType __a, _UIntType __c, _UIntType __m>
template<typename _Sseq > auto std::linear_congruential_engine< _UIntType, __a, __c, __m >::seed (_Sseq & __q) -> _If_seed_seq<_Sseq>

The text says: " Seeds the LCR engine with a value generated by __q.

  • References: std::__lg().
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:
    • __s — The new seed.

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

  • Referenced by: std::linear_congruential_engine< _UIntType, __a, __c, __m >::linear_congruential_engine(), and std::linear_congruential_engine< _UIntType, __a, __c, __m >::linear_congruential_engine(). yes, it lists that twice, and I'm not erasing the manpage's little quirks. 💀
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:
    • __os — The output stream.
    • __lcr — A % 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:
    • __lhs — A linear congruential random number generator object.
    • __rhs — Another linear congruential random number generator object.
  • Returns: true if the infinite sequences of generated values would be equal, false otherwise.
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:
    • __is — The input stream.
    • __lcr — A % linear_congruential_engine random number generator.
  • Returns: __is.

🌟 Member Data Documentation 🌟

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

An increment.

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

The modulus.

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

The multiplier.

💀 Author 💀

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okay that's the whole page, bestie! cute sign-off time: source/version is libstdc++ + 3cxx, and the date field in that footer line isn't actually shown in the text I got — so I'm not inventing one, periodt. mwah 💋✨🎀

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