// Boost next_prior.hpp header file ---------------------------------------// | |
// (C) Copyright Dave Abrahams and Daniel Walker 1999-2003. Distributed under the Boost | |
// Software License, Version 1.0. (See accompanying file | |
// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) | |
// See http://www.boost.org/libs/utility for documentation. | |
// Revision History | |
// 13 Dec 2003 Added next(x, n) and prior(x, n) (Daniel Walker) | |
#ifndef BOOST_NEXT_PRIOR_HPP_INCLUDED | |
#define BOOST_NEXT_PRIOR_HPP_INCLUDED | |
#include <iterator> | |
namespace boost { | |
// Helper functions for classes like bidirectional iterators not supporting | |
// operator+ and operator- | |
// | |
// Usage: | |
// const std::list<T>::iterator p = get_some_iterator(); | |
// const std::list<T>::iterator prev = boost::prior(p); | |
// const std::list<T>::iterator next = boost::next(prev, 2); | |
// Contributed by Dave Abrahams | |
template <class T> | |
inline T next(T x) { return ++x; } | |
template <class T, class Distance> | |
inline T next(T x, Distance n) | |
{ | |
std::advance(x, n); | |
return x; | |
} | |
template <class T> | |
inline T prior(T x) { return --x; } | |
template <class T, class Distance> | |
inline T prior(T x, Distance n) | |
{ | |
std::advance(x, -n); | |
return x; | |
} | |
} // namespace boost | |
#endif // BOOST_NEXT_PRIOR_HPP_INCLUDED |