libcruft-util/random.hpp

58 lines
1.6 KiB
C++

/*
* This file is part of libgim.
*
* libgim is free software: you can redistribute it and/or modify it under the
* terms of the GNU General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option) any later
* version.
*
* libgim is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with libgim. If not, see <http://www.gnu.org/licenses/>.
*
* Copyright 2010 Danny Robson <danny@nerdcruft.net>
*/
#ifndef __UTIL_RANDOM_HPP
#define __UTIL_RANDOM_HPP
#include <iterator>
namespace util {
template <typename T>
T& randomise (T &);
template <typename T, size_t N>
T* randomise (T(&)[N]);
template <typename T>
T random (void);
template <typename T>
typename T::value_type&
choose (T &container) {
typename T::iterator cursor = container.begin ();
typename T::size_type size = container.size ();
typename T::size_type offset = random<typename T::size_type> () % size;
std::advance (cursor, offset);
return *cursor;
}
template <typename T>
typename T::value_type&
choose (T begin, T end) {
typename T::difference_type size = std::distance (begin, end);
std::advance (begin, random<T::size_type> () % size);
return *begin;
}
}
#include "random.ipp"
#endif