Random Numbers

Random numbers are necessary for many domains, e.g., to test software, to generate cryptographic keys or for computer games. The random number facility of C++ consists of two components. There is the generation of the random numbers, and there is the distribution of these random numbers. Both components need the header <random>.

Random number generator

The random number generator generates a random number stream between a minimum and maximum value. This stream is initialized by a “so-called” seed, guaranteeing different sequences of random numbers.

#include <random>
...
std::random_device seed;
std::mt19937 generator(seed());

A random number generator gen of type Generator supports four different requests:

Generator::result_type

Data type of the generated random number.

gen()

Returns a random number.

gen.min()

Returns the minimum random number that can be returned by gen().

gen.max()

Returns the maximum random number...