1// <experimental/random> -*- C++ -*-
2
3// Copyright (C) 2015-2016 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library.  This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 3, or (at your option)
9// any later version.
10
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14// GNU General Public License for more details.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23// <http://www.gnu.org/licenses/>.
24
25/** @file experimental/random
26 *  This is a TS C++ Library header.
27 */
28
29#ifndef _GLIBCXX_EXPERIMENTAL_RANDOM
30#define _GLIBCXX_EXPERIMENTAL_RANDOM 1
31
32#include <random>
33#include <experimental/bits/lfts_config.h>
34
35namespace std {
36namespace experimental {
37inline namespace fundamentals_v2 {
38_GLIBCXX_BEGIN_NAMESPACE_VERSION
39
40#define __cpp_lib_experimental_randint 201511
41
42  inline std::default_random_engine&
43  _S_randint_engine()
44  {
45    static thread_local default_random_engine __eng{random_device{}()};
46    return __eng;
47  }
48
49  // 13.2.2.1, Function template randint
50  template<typename _IntType>
51    inline _IntType
52    randint(_IntType __a, _IntType __b)
53    {
54      static_assert(is_integral<_IntType>::value && sizeof(_IntType) > 1,
55		    "argument must be an integer type");
56      using _Dist = std::uniform_int_distribution<_IntType>;
57      static thread_local _Dist __dist;
58      return __dist(_S_randint_engine(), typename _Dist::param_type{__a, __b});
59    }
60
61  inline void
62  reseed()
63  {
64    _S_randint_engine().seed(random_device{}());
65  }
66
67  inline void
68  reseed(default_random_engine::result_type __value)
69  {
70    _S_randint_engine().seed(__value);
71  }
72
73_GLIBCXX_END_NAMESPACE_VERSION
74} // namespace fundamentals_v2
75} // namespace experimental
76} // namespace std
77
78#endif
79