libcruft-util/random.hpp

51 lines
1.5 KiB
C++
Raw Normal View History

2011-09-13 15:13:55 +10:00
/*
2015-04-13 18:05:28 +10:00
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
2011-09-13 15:13:55 +10:00
*
2015-04-13 18:05:28 +10:00
* http://www.apache.org/licenses/LICENSE-2.0
2011-09-13 15:13:55 +10:00
*
2015-04-13 18:05:28 +10:00
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
2011-09-13 15:13:55 +10:00
*
* Copyright 2016 Danny Robson <danny@nerdcruft.net>
2011-09-13 15:13:55 +10:00
*/
#ifndef __UTIL_RANDOM_HPP
#define __UTIL_RANDOM_HPP
#include <random>
2011-09-13 15:13:55 +10:00
///////////////////////////////////////////////////////////////////////////////
namespace util::rand {
//-------------------------------------------------------------------------
using default_generator = std::minstd_rand;
2012-05-22 14:13:07 +10:00
//-------------------------------------------------------------------------
template <typename Generator = default_generator>
Generator&
thread_engine (void)
{
std::random_device rd;
thread_local Generator gen (rd ());
return gen;
}
//-------------------------------------------------------------------------
template <typename Generator = default_generator, typename T, size_t N>
T&
choose (T (&t)[N], Generator gen = thread_engine<Generator> ())
{
std::uniform_int_distribution<size_t> dist (0, N-1);
return t[dist (gen)];
}
2011-09-13 15:13:55 +10:00
}
#endif