libstdc++-v3/testsuite/26_numerics/random/random_device/cons/token.cc

   1 // { dg-do run { target c++11 } }
   2 // { dg-require-cstdint "" }
   3 //
   4 // 2008-11-24  Edward M. Smith-Rowland <3dw4rd@verizon.net>
   5 //
   6 // Copyright (C) 2008-2024 Free Software Foundation, Inc.
   7 //
   8 // This file is part of the GNU ISO C++ Library.  This library is free
   9 // software; you can redistribute it and/or modify it under the
  10 // terms of the GNU General Public License as published by the
  11 // Free Software Foundation; either version 3, or (at your option)
  12 // any later version.
  13 //
  14 // This library is distributed in the hope that it will be useful,
  15 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 // GNU General Public License for more details.
  18 //
  19 // You should have received a copy of the GNU General Public License along
  20 // with this library; see the file COPYING3.  If not see
  21 // <http://www.gnu.org/licenses/>.
  22
  23 // C++11 26.5.6 class random_device [rand.device]
  24
  25 #include <random>
  26 #include <stdexcept>
  27 #include <cstdio>
  28 #include <testsuite_hooks.h>
  29 #include <testsuite_random.h>
  30
  31 void
  32 test01()
  33 {
  34   std::random_device x("default");
  35   using result_type = std::random_device::result_type;
  36   VERIFY( x.min() == std::numeric_limits<result_type>::min() );
  37   VERIFY( x.max() == std::numeric_limits<result_type>::max() );
  38 }
  39
  40 void
  41 test02()
  42 {
  43 #ifdef _GLIBCXX_USE_DEV_RANDOM
  44   std::random_device x1("/dev/urandom");
  45   std::random_device x2("/dev/random");
  46   VERIFY( x1() != x2() || x1() != x2() );
  47 #endif
  48 }
  49
  50 void
  51 test03()
  52 {
  53   // At least one of these tokens should be valid.
  54   const std::string tokens[] = {
  55     "rdseed", "rdrand", "darn",
  56     "rand_s", "/dev/urandom", "/dev/random",
  57     "getentropy", "arc4random",
  58     "mt19937", "prng"
  59   };
  60   int count = 0;
  61   for (const std::string& token : tokens)
  62   {
  63     std::printf("checking std::random_device(\"%s\"):\t", token.c_str());
  64     if (__gnu_test::random_device_available(token))
  65     {
  66       std::puts("yes");
  67       ++count;
  68     }
  69     else
  70       std::puts("no");
  71   }
  72   VERIFY( count != 0 );
  73 }
  74
  75 void
  76 test04()
  77 {
  78   if (__gnu_test::random_device_available("mt19937"))
  79   {
  80     std::random_device x("mt19937");
  81     std::random_device::result_type xval = x();
  82
  83     // If "mt19937" is a valid token then numeric seeds should be too.
  84     std::random_device x1("0");
  85     std::random_device x2("1234");
  86     std::random_device x3("0xc0fefe");
  87     VERIFY( xval != x1() );
  88     VERIFY( x2() != x3() );
  89   }
  90 }
  91
  92 int main()
  93 {
  94   test01();
  95   test02();
  96   test03();
  97   test04();
  98 }