libcxx/test/std/numerics/rand/rand.device/entropy.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // UNSUPPORTED: no-random-device
  10
  11 // <random>
  12
  13 // class random_device;
  14
  15 // double entropy() const;
  16
  17 #include <random>
  18 #include <cassert>
  19 #include <climits>
  20
  21 #include "test_macros.h"
  22
  23 int main(int, char**) {
  24   std::random_device r;
  25   double e = r.entropy();
  26   assert(e >= 0);
  27   assert(e <= sizeof(typename std::random_device::result_type) * CHAR_BIT);
  28
  29   return 0;
  30 }