thrust::random::uniform_int_distribution

Defined in thrust/random/uniform_int_distribution.h

template<typename IntType = int> class uniform_int_distribution

A uniform_int_distribution random number distribution produces signed or unsigned integer uniform random numbers from a given range.

The following code snippet demonstrates examples of using a uniform_int_distribution with a random number engine to produce random integers drawn from a given range:

#include <thrust/random/linear_congruential_engine.h>
#include <thrust/random/uniform_int_distribution.h>

int main()
{
  // create a minstd_rand object to act as our source of randomness
  thrust::minstd_rand rng;

  // create a uniform_int_distribution to produce ints from [-7,13]
  thrust::uniform_int_distribution<int> dist(-7,13);

  // write a random number from the range [-7,13] to standard output
  std::cout << dist(rng) << std::endl;

  // write the range of the distribution, just in case we forgot
  std::cout << dist.min() << std::endl;

  // -7 is printed

  std::cout << dist.max() << std::endl;

  // 13 is printed

  // write the parameters of the distribution (which happen to be the bounds) to standard output
  std::cout << dist.a() << std::endl;

  // -7 is printed

  std::cout << dist.b() << std::endl;

  // 13 is printed

  return 0;
}

Template Parameters: IntType – The type of integer to produce.

Public Types

typedef IntType result_type: The type of the integer produced by this uniform_int_distribution.

typedef thrust::pair<IntType, IntType> param_type: The type of the object encapsulating this uniform_int_distribution's parameters.

Public Functions

explicit uniform_int_distribution(IntType a = 0, IntType b = THRUST_NS_QUALIFIER::detail::integer_traits<IntType>::const_max)

This constructor creates a new uniform_int_distribution from two values defining the range of the distribution.

Parameters

a – The smallest integer to potentially produce. Defaults to 0.
b – The largest integer to potentially produce. Defaults to the largest representable integer in the platform.

explicit uniform_int_distribution(const param_type &parm)

This constructor creates a new uniform_int_distribution from a param_type object encapsulating the range of the distribution.

Parameters: parm – A param_type object encapsulating the parameters (i.e., the range) of the distribution.

void reset(): This does nothing. It is included to conform to the requirements of the RandomDistribution concept.

template<typename UniformRandomNumberGenerator> result_type operator()(UniformRandomNumberGenerator &urng)

This method produces a new uniform random integer drawn from this uniform_int_distribution's range using a UniformRandomNumberGenerator as a source of randomness.

Parameters: urng – The UniformRandomNumberGenerator to use as a source of randomness.

template<typename UniformRandomNumberGenerator> result_type operator()(UniformRandomNumberGenerator &urng, const param_type &parm)

This method produces a new uniform random integer as if by creating a new uniform_int_distribution from the given param_type object, and calling its operator() method with the given UniformRandomNumberGenerator as a source of randomness.

Parameters

urng – The UniformRandomNumberGenerator to use as a source of randomness.
parm – A param_type object encapsulating the parameters of the uniform_int_distribution to draw from.

result_type a() const

This method returns the value of the parameter with which this uniform_int_distribution was constructed.

Returns: The lower bound of this uniform_int_distribution's range.

result_type b() const

This method returns the value of the parameter with which this uniform_int_distribution was constructed.

Returns: The upper bound of this uniform_int_distribution's range.

param_type param() const

This method returns a param_type object encapsulating the parameters with which this uniform_int_distribution was constructed.

Returns: A param_type object enapsulating the range of this uniform_int_distribution.

void param(const param_type &parm)

This method changes the parameters of this uniform_int_distribution using the values encapsulated in a given param_type object.

Parameters: parm – A param_type object encapsulating the new range of this uniform_int_distribution.

result_type min() const

This method returns the smallest integer this uniform_int_distribution can potentially produce.

Returns: The lower bound of this uniform_int_distribution's range.

result_type max() const

This method returns the largest integer this uniform_int_distribution can potentially produce.

Returns: The upper bound of this uniform_int_distribution's range.