Varianti

std::random_device::random_device

Da cppreference.com.

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Numeri libreria
Comuni funzioni matematiche
Virgola mobile ambiente
I numeri complessi
Array numerici
Pseudo-casuale generazione
In fase di compilazione aritmetica razionale (C++11)
Generici operazioni numeriche
Original:
Generic numeric operations
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iota(C++11)
accumulate
inner_product
adjacent_difference
partial_sum
 
Pseudo-casuale generazione
Motori e adattatori del motore
Original:
Engines and engine adaptors
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linear_congruential_engine(C++11)
mersenne_twister_engine(C++11)
subtract_with_carry_engine(C++11)
discard_block_engine(C++11)
independent_bits_engine(C++11)
shuffle_order_engine(C++11)
Generatori
Original:
Generators
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random_device(C++11)
Distribuzioni
Original:
Distributions
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Distribuzioni uniformi
Original:
Uniform distributions
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uniform_int_distribution(C++11)
uniform_real_distribution(C++11)
generate_canonical(C++11)
Bernoulli distribuzioni
Original:
Bernoulli distributions
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bernoulli_distribution(C++11)
binomial_distribution(C++11)
negative_binomial_distribution(C++11)
geometric_distribution(C++11)
Poisson distribuzioni
Original:
Poisson distributions
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poisson_distribution(C++11)
exponential_distribution(C++11)
gamma_distribution(C++11)
weibull_distribution(C++11)
extreme_value_distribution(C++11)
Distribuzioni normali
Original:
Normal distributions
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normal_distribution(C++11)
lognormal_distribution(C++11)
chi_squared_distribution(C++11)
cauchy_distribution(C++11)
fisher_f_distribution(C++11)
student_t_distribution(C++11)
Distribuzioni di campionamento
Original:
Sampling distributions
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discrete_distribution(C++11)
piecewise_constant_distribution(C++11)
piecewise_linear_distribution(C++11)
Seed Sequenze
Original:
Seed Sequences
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seed_seq(C++11)
Libreria C
Original:
C library
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rand
srand
RAND_MAX
 
std::random_device
Membri funzioni
Original:
Member functions
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random_device::random_device
Generazione
Original:
Generation
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random_device::operator()
Caratteristiche
Original:
Characteristics
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random_device::entropy
random_device::min
random_device::max
 
<tbody> </tbody>
explicit random_device(const std::string& token = /*implementation-defined*/ );
(dal C++11)
Costruisce un nuovo oggetto std::random_device, avvalendosi della token argomento, se previsto, in attuazione definito modo.
Original:
Constructs a new std::random_device object, making use of the argument token, if provided, in implementation-defined manner.
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Applicazione tipica su un sistema Linux, per esempio, si aspetta token di essere il nome di un dispositivo a caratteri che produce numeri casuali lettura da, con il valore predefinito "/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".
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Eccezioni

Genera un applicazione definite le eccezioni derivate da std::exception in caso di fallimento.
Original:
Throws an implementation-defined exceptions derived from std::exception on failure.
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Esempio

Vengono illustrati i due tipi comunemente disponibili di std::random_device su 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';
}

Output:

7 10 7 0 4 4 6 9 4 7 
2 4 10 6 3 2 0 6 3 7