std::seed_seq (3) - Linux Manuals

std::seed_seq: std::seed_seq

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 std::uint_least32_t

Member functions

              constructs and seeds the std::seed_seq object
constructor (public member function)

operator= not copy-assignable
              (public member function)
(deleted)
              calculates the bias-eliminated, evenly distributed 32-bit values
generate (public member function)
              obtains the number of 32-bit values stored in std::seed_seq
size (public member function)
              obtains the 32-bit values stored in std::seed_seq
param (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