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