// 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