std::uniform_int_distribution

 

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std::uniform_int_distribution

Member functions

uniform_int_distribution::uniform_int_distribution (C++11)

uniform_int_distribution::reset (C++11)

Generation

uniform_int_distribution::operator() (C++11)

Characteristics

uniform_int_distribution::auniform_int_distribution::b (C++11)(C++11)

uniform_int_distribution::param (C++11)

uniform_int_distribution::min (C++11)

uniform_int_distribution::max (C++11)

Non-member functions

operator==operator!= (C++11)(C++11)(until C++20)

operator<<operator>> (C++11)(C++11)

 

Defined in header <random>
template< class IntType = int > class uniform_int_distribution;		(since C++11)

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

\({\small P(i|a,b) =}\frac{1}{b - a + 1}\)P(i|a,b) =

1

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(C++11)	IntType
param_type(C++11)	the type of the parameter set, see RandomNumberDistribution.

Member functions

(constructor) (C++11)	constructs new distribution (public member function)
reset (C++11)	resets the internal state of the distribution (public member function)
Generation
operator() (C++11)	generates the next random number in the distribution (public member function)
Characteristics
ab	returns the distribution parameters (public member function)
param (C++11)	gets or sets the distribution parameter object (public member function)
min (C++11)	returns the minimum potentially generated value (public member function)
max (C++11)	returns the maximum potentially generated value (public member function)

Non-member functions

operator==operator!= (C++11)(C++11)(removed in C++20)	compares two distribution objects (function)
operator<<operator>> (C++11)	performs stream input and output on pseudo-random number distribution (function template)

Example

This program simulates throwing 6-sided dice.

Run this code

#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<> distrib(1, 6);
 
    for (int n=0; n<10; ++n)
        //Use `distrib` to transform the random unsigned int generated by gen into an int in [1, 6]
        std::cout << distrib(gen) << ' ';
    std::cout << '\n';
}

Possible output:

1 1 6 5 2 2 5 5 6 2