Move test into test/std subdirectory.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@224658 91177308-0d34-0410-b5e6-96231b3b80d8

test/std/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/eval_param.pass.cpp

@@ -0,0 +1,45 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// REQUIRES: long_tests
+
+// <random>
+
+// template<class IntType = int>
+// class discrete_distribution
+
+// template<class _URNG> result_type operator()(_URNG& g, const param_type& parm);
+
+#include <random>
+#include <vector>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type P;
+        typedef std::minstd_rand G;
+        G g;
+        D d;
+        double p0[] = {.3, .1, .6};
+        P p(p0, p0+3);
+        const int N = 10000000;
+        std::vector<D::result_type> u(3);
+        for (int i = 0; i < N; ++i)
+        {
+            D::result_type v = d(g, p);
+            assert(0 <= v && v <= 2);
+            u[v]++;
+        }
+        std::vector<double> prob = p.probabilities();
+        for (int i = 0; i <= 2; ++i)
+            assert(std::abs((double)u[i]/N - prob[i]) / prob[i] < 0.001);
+    }
+}