std::seed_seq::seed_seq

 

C++

Language

Standard library headers

Concepts

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

 

Numerics library

Common mathematical functions

Special mathematical functions

Floating-point environment (C++11)

Complex numbers

Numeric arrays

Pseudo-random number generation

Compile-time rational arithmetic (C++11)

Numeric algorithms

gcd (C++17)

lcm (C++17)

Generic numeric operations

iota (C++11)

accumulate

inner_product

adjacent_difference

partial_sum

 

Pseudo-random number generation

Engines and engine adaptors

linear_congruential_engine (C++11)

mersenne_twister_engine (C++11)

subtract_with_carry_engine (C++11)

discard_block_engine (C++11)

independent_bits_engine (C++11)

shuffle_order_engine (C++11)

Generators

random_device (C++11)

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)

Seed Sequences

seed_seq (C++11)

C library

rand

srand

RAND_MAX

 

std::seed_seq

Member functions

seed_seq::seed_seq

seed_seq::generate

seed_seq::size

seed_seq::param

 

seed_seq();	(1)	(since C++11)
seed_seq( const seed_seq& ) = delete;	(2)	(since C++11)
template< class InputIt > seed_seq( InputIt begin, InputIt end );	(3)	(since C++11)
template< class T > seed_seq( std::initializer_list<T> il );	(4)	(since C++11)

1) The default constructor creates a std::seed_seq object with an initial seed sequence of length zero.

2) The copy constructor is deleted: std::seed_seq is not copyable.

3) Constructs a std::seed_seq with the initial seed sequence obtained by iterating over the range [begin, end) and copying the values obtained by dereferencing the iterator, modulo 232
(that is, the lower 32 bits are copied)

4) Equivalent to seed_seq(il.begin(), il.end()). This constructor enables list-initialization.

Parameters

begin, end	-	the initial seed sequence represented as a pair of input iterators whose std::iterator_traits<>::value_type is an integer type
il	-	std::initializer_list of objects of integer type, providing the iniial seed sequence
Type requirements
- InputIt must meet the requirements of InputIterator.

Exceptions

1) Does not throw

Example

Run this code

#include <random>
#include <sstream>
#include <iterator>
int main()
{
    std::seed_seq s1; // default-constructible
    std::seed_seq s2{1, 2, 3}; // can use list-initialization
    std::seed_seq s3 = {-1, 0, 1}; // another form of list-initialization
    int a[10] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
    std::seed_seq s4(a, a + 10); // can use iterators
    std::istringstream buf("1 2 3 4 5"); 
    std::istream_iterator<int> beg(buf), end;
    std::seed_seq s5(beg, end); // even stream input iterators
}