std::mersenne_twister_engine<UIntType,w,n,m,r,a,u,d,s,b,t,c,l,f>::seed

 

C++

Compiler support

Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Metaprogramming library (C++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (C++17)

Regular expressions library (C++11)

Concurrency support library (C++11)

Execution support library (C++26)

Technical specifications

Symbols index

External libraries

 

Numerics library

Common mathematical functions
Mathematical special functions (C++17)
Mathematical constants (C++20)
Basic linear algebra algorithms (C++26)
Floating-point environment (C++11)
Complex numbers
Numeric array (valarray)
Pseudo-random number generation
Factor operations
gcd (C++17)	lcm (C++17)
Interpolations
midpoint (C++20)	lerp (C++20)
Saturation arithmetic
add_sat (C++26) sub_sat (C++26) saturate_cast (C++26)	mul_sat (C++26) div_sat (C++26)
Generic numeric operations
iota (C++11) ranges::iota (C++23) accumulate inner_product adjacent_difference partial_sum	reduce (C++17) transform_reduce (C++17) inclusive_scan (C++17) exclusive_scan (C++17) transform_inclusive_scan (C++17) transform_exclusive_scan (C++17)
Bit operations
has_single_bit (C++20)     bit_cast (C++20) bit_ceil (C++20) bit_floor (C++20) bit_width (C++20) rotl (C++20) rotr (C++20)	popcount (C++20) countl_zero (C++20) countl_one (C++20) countr_zero (C++20) countr_one (C++20) byteswap (C++23) endian (C++20)

 

Pseudo-random number generation

Uniform random bit generators   uniform_random_bit_generator (C++20) Random number engines linear_congruential_engine (C++11) mersenne_twister_engine (C++11) subtract_with_carry_engine (C++11) philox_engine (C++26) Random number engine adaptors discard_block_engine (C++11) independent_bits_engine (C++11) shuffle_order_engine (C++11) Predefined random number generators Non-deterministic random numbers random_device (C++11) Utilities generate_canonical (C++11) seed_seq (C++11) Random number algorithms ranges::generate_random (C++26) C random library rand    srand    RAND_MAX

Random number distributions Uniform distributions uniform_int_distribution (C++11) uniform_real_distribution (C++11) generate_canonical (C++11) Bernoulli distributions bernoulli_distribution (C++11) binomial_distribution (C++11) negative_binomial_distribution (C++11) geometric_distribution (C++11) Poisson distributions poisson_distribution (C++11) exponential_distribution (C++11) gamma_distribution (C++11) weibull_distribution (C++11) extreme_value_distribution (C++11) Normal distributions normal_distribution (C++11) lognormal_distribution (C++11) chi_squared_distribution (C++11) cauchy_distribution (C++11) fisher_f_distribution (C++11) student_t_distribution (C++11) Sampling distributions discrete_distribution (C++11) piecewise_constant_distribution (C++11) piecewise_linear_distribution (C++11)

 

std::mersenne_twister_engine

Member functions

mersenne_twister_engine::mersenne_twister_engine

mersenne_twister_engine::seed

Generation

mersenne_twister_engine::operator()

mersenne_twister_engine::discard

Characteristics

mersenne_twister_engine::min

mersenne_twister_engine::max

Non-member functions

operator==operator!= (C++11)(C++11)(until C++20)

operator<<operator>> (C++11)(C++11)

 

void seed( result_type value = default_seed );	(1)	(since C++11)
template< class SeedSeq > void seed( SeedSeq& seq );	(2)	(since C++11)

Sets the state of the random-number engine.

1) Right after the state is set, *this == std::mersenne_twister_engine(value) is true.

2) Right after the state is set, *this == std::mersenne_twister_engine(seq) is true.

Parameters

value	-	seed value to use to set the state
seq	-	seed sequence to use to set the state

Exceptions

2) If SeedSeq is not std::seed_seq, throws the exceptions thrown by the seq.generate call.

Complexity

1) Same as std::mersenne_twister_engine(value).

2) Same as std::mersenne_twister_engine(seq).

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR	Applied to	Behavior as published	Correct behavior
LWG 2181	C++11	overload (2) would not throw even if the seq.generate call throws	propagates the exception

See also

(constructor)

constructs the engine (public member function)

Example

Run this code

#include <iostream>
#include <random>
 
int main()
{
    std::mt19937 gen;
 
    // Seed the engine with an unsigned int
    gen.seed(1);
    std::cout << "after seed by 1: " << gen() << '\n';
 
    // Seed the engine with two unsigned ints
    std::seed_seq sseq{1, 2};
    gen.seed(sseq);
    std::cout << "after seed by {1,2}: " << gen() << '\n';
}

Possible output:

after seed by 1: 1791095845
after seed by {1,2}: 3127717181