libcxx/test/std/numerics/rand/rand.util/rand.util.seedseq/iterator.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 // <random>
  10
  11 // class seed_seq;
  12
  13 // template<class InputIterator>
  14 //     seed_seq(InputIterator begin, InputIterator end);
  15
  16 #include <random>
  17 #include <cassert>
  18
  19 #include "test_macros.h"
  20
  21 void test()
  22 {
  23   {
  24     unsigned a[5] = {5, 4, 3, 2, 1};
  25     std::seed_seq s(a, a+5);
  26     assert(s.size() == 5);
  27
  28     unsigned b[5] = {0};
  29     s.param(b);
  30     assert(b[0] == 5);
  31     assert(b[1] == 4);
  32     assert(b[2] == 3);
  33     assert(b[3] == 2);
  34     assert(b[4] == 1);
  35   }
  36   {
  37     // Test truncation to 32 bits
  38     unsigned long long a[4] = {
  39       0x1234000056780000uLL,
  40       0x0000001234567800uLL,
  41       0xFFFFFFFFFFFFFFFFuLL,
  42       0x0000000180000000uLL,
  43     };
  44     std::seed_seq s(a, a+4);
  45     assert(s.size() == 4);
  46
  47     unsigned b[4] = {0};
  48     s.param(b);
  49     assert(b[0] == 0x56780000u);
  50     assert(b[1] == 0x34567800u);
  51     assert(b[2] == 0xFFFFFFFFu);
  52     assert(b[3] == 0x80000000u);
  53   }
  54 #if TEST_STD_VER >= 11
  55   {
  56     // Test uniform initialization syntax (LWG 3422)
  57     unsigned a[3] = {1, 2, 3};
  58     std::seed_seq s{a, a+3};  // uniform initialization
  59     assert(s.size() == 3);
  60
  61     unsigned b[3] = {0};
  62     s.param(b);
  63     assert(b[0] == 1);
  64     assert(b[1] == 2);
  65     assert(b[2] == 3);
  66   }
  67 #endif // TEST_STD_VER >= 11
  68 }
  69
  70 int main(int, char**)
  71 {
  72   test();
  73
  74   return 0;
  75 }