The following code example is taken from the book
The C++ Standard Library - A Tutorial and Reference, 2nd Edition
by Nicolai M. Josuttis, Addison Wesley Longman, 2012
Copyright © 2012 by Pearson Education, Inc. and Nicolai M. Josuttis
#include <random>
#include <map>
#include <string>
#include <iostream>
#include <iomanip>
template <typename Distr, typename Eng>
void distr (Distr d, Eng e, const std::string& name)
{
// print min, max and four example values
std::cout << name << ":" << std::endl;
std::cout << "- min(): " << d.min() << std::endl;
std::cout << "- max(): " << d.max() << std::endl;
std::cout << "- values: " << d(e) << ' ' << d(e) << ' '
<< d(e) << ' ' << d(e) << std::endl;
// count the generated values (converted to integral values)
std::map<long long,int> valuecounter;
for (int i=0; i<200000; ++i) {
valuecounter[d(e)]++;
}
// and print the resulting distribution
std::cout << "====" << std::endl;
for (auto elem : valuecounter) {
std::cout << std::setw(3) << elem.first << ": "
<< elem.second << std::endl;
}
std::cout << "====" << std::endl;
std::cout << std::endl;
}
int main()
{
std::knuth_b e;
std::uniform_real_distribution<> ud(0, 10);
distr(ud,e,"uniform_real_distribution");
std::normal_distribution<> nd;
distr(nd,e,"normal_distribution");
std::exponential_distribution<> ed;
distr(ed,e,"exponential_distribution");
std::gamma_distribution<> gd;
distr(gd,e,"gamma_distribution");
}