1//===----------------------------------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is dual licensed under the MIT and the University of Illinois Open
6// Source Licenses. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10// <random>
11
12// template<class IntType = int>
13// class discrete_distribution
14
15// template<class _URNG> result_type operator()(_URNG& g, const param_type& parm);
16
17#include <random>
18#include <vector>
19#include <cassert>
20
21int main()
22{
23    {
24        typedef std::discrete_distribution<> D;
25        typedef D::param_type P;
26        typedef std::minstd_rand G;
27        G g;
28        D d;
29        double p0[] = {.3, .1, .6};
30        P p(p0, p0+3);
31        const int N = 10000000;
32        std::vector<D::result_type> u(3);
33        for (int i = 0; i < N; ++i)
34        {
35            D::result_type v = d(g, p);
36            assert(0 <= v && v <= 2);
37            u[v]++;
38        }
39        std::vector<double> prob = p.probabilities();
40        for (int i = 0; i <= 2; ++i)
41            assert(std::abs((double)u[i]/N - prob[i]) / prob[i] < 0.001);
42    }
43}
44