< cpp‎ | numeric‎ | random
Pseudo-random number generation
Engines and engine adaptors
Uniform distributions
Bernoulli distributions
Poisson distributions
Normal distributions
Sampling distributions
Seed Sequences
C library
Defined in header <random>
template< class IntType = int >
class uniform_int_distribution;
(since C++11)

Produces random integer values i, uniformly distributed on the closed interval [a, b], that is, distributed according to the discrete probability function

P(i|a,b) =
b − a + 1

std::uniform_int_distribution satisfies all requirements of RandomNumberDistribution

Template parameters

IntType - The result type generated by the generator. The effect is undefined if this is not one of short, int, long, long long, unsigned short, unsigned int, unsigned long, or unsigned long long.

Member types

Member type Definition
result_type IntType
param_type the type of the parameter set, see RandomNumberDistribution.

Member functions

constructs new distribution
(public member function)
resets the internal state of the distribution
(public member function)
generates the next random number in the distribution
(public member function)
returns the distribution parameters
(public member function)
gets or sets the distribution parameter object
(public member function)
returns the minimum potentially generated value
(public member function)
returns the maximum potentially generated value
(public member function)

Non-member functions

compares two distribution objects
performs stream input and output on pseudo-random number distribution
(function template)


This program simulates throwing 6-sided dice.

#include <random>
#include <iostream>
int main()
    std::random_device rd;  //Will be used to obtain a seed for the random number engine
    std::mt19937 gen(rd()); //Standard mersenne_twister_engine seeded with rd()
    std::uniform_int_distribution<> dis(1, 6);
    for (int n=0; n<10; ++n)
        //Use dis to transform the random unsigned int generated by gen into an int in [1, 6]
        std::cout << dis(gen) << ' ';
    std::cout << '\n';

Possible output:

1 1 6 5 2 2 5 5 6 2