45 lines
1.4 KiB
Plaintext
45 lines
1.4 KiB
Plaintext
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//---------------------------------------------------------------------------//
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// Copyright (c) 2013 Kyle Lutz <kyle.r.lutz@gmail.com>
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//
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// Distributed under the Boost Software License, Version 1.0
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// See accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt
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//
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// See http://boostorg.github.com/compute for more information.
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//---------------------------------------------------------------------------//
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#ifndef BOOST_COMPUTE_DETAIL_ITERATOR_RANGE_SIZE_H
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#define BOOST_COMPUTE_DETAIL_ITERATOR_RANGE_SIZE_H
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#include <cstddef>
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#include <algorithm>
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#include <iterator>
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namespace boost {
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namespace compute {
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namespace detail {
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// This is a convenience function which returns the size of a range
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// bounded by two iterators. This function has two differences from
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// the std::distance() function: 1) the return type (size_t) is
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// unsigned, and 2) the return value is always positive.
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template<class Iterator>
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inline size_t iterator_range_size(Iterator first, Iterator last)
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{
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typedef typename
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std::iterator_traits<Iterator>::difference_type
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difference_type;
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difference_type difference = std::distance(first, last);
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return static_cast<size_t>(
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(std::max)(difference, static_cast<difference_type>(0))
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);
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}
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} // end detail namespace
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} // end compute namespace
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} // end boost namespace
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#endif // BOOST_COMPUTE_DETAIL_ITERATOR_RANGE_SIZE_H
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