ceph/src/boost/libs/range/include/boost/range/algorithm_ext/copy_n.hpp

   1 //  Copyright Neil Groves 2009. Use, modification and
   2 //  distribution is subject to the Boost Software License, Version
   3 //  1.0. (See accompanying file LICENSE_1_0.txt or copy at
   4 //  http://www.boost.org/LICENSE_1_0.txt)
   5 //
   6 //
   7 // For more information, see http://www.boost.org/libs/range/
   8 //
   9 #ifndef BOOST_RANGE_ALGORITHM_COPY_N_HPP_INCLUDED
  10 #define BOOST_RANGE_ALGORITHM_COPY_N_HPP_INCLUDED
  11
  12 #include <boost/assert.hpp>
  13 #include <boost/concept_check.hpp>
  14 #include <boost/range/begin.hpp>
  15 #include <boost/range/end.hpp>
  16 #include <boost/range/concepts.hpp>
  17 #include <boost/range/distance.hpp>
  18 #include <boost/range/iterator.hpp>
  19 #include <boost/range/iterator_range.hpp>
  20 #include <algorithm>
  21
  22 namespace boost
  23 {
  24     namespace range
  25     {
  26
  27 /// \brief template function copy
  28 ///
  29 /// range-based version of the copy std algorithm
  30 ///
  31 /// \pre SinglePassRange is a model of the SinglePassRangeConcept
  32 /// \pre OutputIterator is a model of the OutputIteratorConcept
  33 /// \pre 0 <= n <= distance(rng)
  34 template< class SinglePassRange, class Size, class OutputIterator >
  35 inline OutputIterator copy_n(const SinglePassRange& rng, Size n, OutputIterator out)
  36 {
  37     BOOST_RANGE_CONCEPT_ASSERT(( SinglePassRangeConcept<const SinglePassRange> ));
  38     BOOST_ASSERT( n <= static_cast<Size>(::boost::distance(rng)) );
  39     BOOST_ASSERT( n >= static_cast<Size>(0) );
  40
  41     BOOST_DEDUCED_TYPENAME range_iterator<const SinglePassRange>::type source = ::boost::begin(rng);
  42
  43     for (Size i = 0; i < n; ++i, ++out, ++source)
  44         *out = *source;
  45
  46     return out;
  47 }
  48
  49     } // namespace range
  50     using ::boost::range::copy_n;
  51 } // namespace boost
  52
  53 #endif // include guard