NAME¶

std::seed_seq - std::seed_seq

Synopsis¶

Defined in header <random>
class seed_seq; (since C++11)

std::seed_seq consumes a sequence of integer-valued data and produces a requested
number of unsigned integer values i, 0 ≤ i < 232
, based on the consumed data. The produced values are distributed over the entire
32-bit range even if the consumed values are close.

It provides a way to seed a large number of random number engines or to seed a
generator that requires a lot of entropy, given a small seed or a poorly distributed
initial seed sequence.

std::seed_seq meets the requirements of SeedSequence.

Member types¶

Member type Definition
result_type(C++11) std::uint_least32_t

Member functions¶

constructor constructs and seeds the std::seed_seq object
(C++11) (public member function)
operator= seed_seq is not assignable
[deleted](C++11) (public member function)
generate calculates the bias-eliminated, evenly distributed 32-bit values
(C++11) (public member function)
size obtains the number of 32-bit values stored in std::seed_seq
(C++11) (public member function)
param obtains the 32-bit values stored in std::seed_seq
(C++11) (public member function)

Example¶

// Run this code

#include <random>
#include <cstdint>
#include <iostream>

int main()
{
std::seed_seq seq{1,2,3,4,5};
std::vector<std::uint32_t> seeds(10);
seq.generate(seeds.begin(), seeds.end());
for (std::uint32_t n : seeds) {
std::cout << n << '\n';
}
}

Output:¶

4204997637
4246533866
1856049002
1129615051
690460811
1075771511
46783058
3904109078
1534123438
1495905678