std::random_device::random_device
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<metanoindex/>
<tbody> </tbody> explicit random_device(const std::string& token = /*implementation-defined*/ ); |
(desde C++11) | |
Constrói um objeto std::random_device novo, fazendo uso da
token argumento, se incluído, em aplicação definida maneira. Original:
Constructs a new std::random_device object, making use of the argument
token, if provided, in implementation-defined manner. The text has been machine-translated via Google Translate.
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Implementação típica em um sistema Linux, por exemplo, espera
token para ser o nome de um dispositivo de caráter que produz números aleatórios quando ler, com o valor padrão "/dev/urandom".Original:
Typical implementation on a Linux system, for example, expects
token to be the name of a character device that produces random numbers when read from, with the default value "/dev/urandom".The text has been machine-translated via Google Translate.
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Exceções
Lança uma exceção definida pela implementação derivados de std::exception em caso de falha.
Original:
Throws an implementation-defined exceptions derived from std::exception on failure.
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Exemplo
Demonstra os dois tipos comumente disponíveis de
std::random_device em Linux
Original:
Demonstrates the two commonly available types of
std::random_device on Linux
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#include <iostream>
#include <random>
int main()
{
std::uniform_int_distribution<int> d(0, 10);
std::random_device rd1; // uses /dev/urandom
for(int n = 0; n < 10; ++n)
std::cout << d(rd1) << ' ';
std::cout << '\n';
std::random_device rd2("/dev/random"); // much slower on Linux
for(int n = 0; n < 10; ++n)
std::cout << d(rd2) << ' ';
std::cout << '\n';
}
Saída:
7 10 7 0 4 4 6 9 4 7
2 4 10 6 3 2 0 6 3 7