整理

include/boost/algorithm/cxx11/copy_n.hpp

@@ -0,0 +1,37 @@
+/* 
+   Copyright (c) Marshall Clow 2011-2012.
+
+   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)
+*/
+
+/// \file  copy_n.hpp
+/// \brief Copy n items from one sequence to another
+/// \author Marshall Clow
+
+#ifndef BOOST_ALGORITHM_COPY_N_HPP
+#define BOOST_ALGORITHM_COPY_N_HPP
+
+#include <boost/config.hpp>
+
+namespace boost { namespace algorithm {
+
+/// \fn copy_n ( InputIterator first, Size n, OutputIterator result )
+/// \brief Copies exactly n (n > 0) elements from the range starting at first to
+///     the range starting at result.
+/// \return         The updated output iterator
+/// 
+/// \param first    The start of the input sequence
+/// \param n        The number of elements to copy
+/// \param result   An output iterator to write the results into
+/// \note           This function is part of the C++2011 standard library.
+template <typename InputIterator, typename Size, typename OutputIterator>
+BOOST_CXX14_CONSTEXPR OutputIterator copy_n ( InputIterator first, Size n, OutputIterator result )
+{
+    for ( ; n > 0; --n, ++first, ++result )
+        *result = *first;
+    return result;
+}
+}} // namespace boost and algorithm
+
+#endif  // BOOST_ALGORITHM_COPY_IF_HPP