std::seed_seq
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 32-bit unsigned integer values, 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.
Nested types
| Type | Definition |
|---|---|
result_type |
std::uint_least32_t |
Data members
| Member | Description |
|---|---|
std::vector<result_type> v | the underlying seed sequence (exposition-only member object*) |
Member functions
constructs and seeds the std::seed_seq object (public member function) |
|
|
operator=
[deleted] |
std::seed_seq is not assignable (public member function) |
| calculates the bias-eliminated, evenly distributed 32-bit values (public member function) |
|
| obtains the number of stored 32-bit values (public member function) |
|
| copies all stored 32-bit values (public member function) |
Example
#include <cstdint>
#include <iostream>
#include <random>
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';
}
Possible output:
4204997637 4246533866 1856049002 1129615051 690460811 1075771511 46783058 3904109078 1534123438 1495905678
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