std::seed_seq
Defined in header <random> |
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(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
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(C++11)
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constructs and seeds the std::seed_seq object (public member function) |
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operator=
[deleted] (C++11)
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seed_seq is not assignable (public member function) |
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(C++11)
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calculates the bias-eliminated, evenly distributed 32-bit values (public member function) |
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(C++11)
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obtains the number of 32-bit values stored in std::seed_seq (public member function) |
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(C++11)
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obtains the 32-bit values stored in std::seed_seq (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
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https://en.cppreference.com/w/cpp/numeric/random/seed_seq