libcxx/test/std/numerics/rand/rand.device/eval.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 // result_type operator()();
  16
  17 #include <random>
  18 #include <cassert>
  19 #include <string>
  20 #include <system_error>
  21
  22 #include "test_macros.h"
  23
  24 int main(int, char**)
  25 {
  26     {
  27         std::random_device r;
  28         std::random_device::result_type e = r();
  29         ((void)e); // Prevent unused warning
  30     }
  31
  32     // When using the `/dev/urandom` implementation, make sure that we throw
  33     // an exception when we hit EOF while reading the custom-provided file.
  34 #if !defined(TEST_HAS_NO_EXCEPTIONS) && defined(_LIBCPP_USING_DEV_RANDOM)
  35     {
  36         std::random_device r("/dev/null");
  37         try {
  38             (void)r();
  39             LIBCPP_ASSERT(false);
  40         } catch (const std::system_error&) {
  41         }
  42     }
  43 #endif
  44
  45   return 0;
  46 }