boost/algorithm/string/detail/util.hpp

   1 //  Boost string_algo library util.hpp header file  ---------------------------//
   2
   3 //  Copyright Pavol Droba 2002-2003.
   4 //
   5 // Distributed under the Boost Software License, Version 1.0.
   6 //    (See accompanying file LICENSE_1_0.txt or copy at
   7 //          http://www.boost.org/LICENSE_1_0.txt)
   8
   9 //  See http://www.boost.org/ for updates, documentation, and revision history.
  10
  11 #ifndef BOOST_STRING_UTIL_DETAIL_HPP
  12 #define BOOST_STRING_UTIL_DETAIL_HPP
  13
  14 #include <boost/algorithm/string/config.hpp>
  15 #include <functional>
  16 #include <boost/range/iterator_range_core.hpp>
  17
  18 namespace boost {
  19     namespace algorithm {
  20         namespace detail {
  21
  22 //  empty container  -----------------------------------------------//
  23
  24             //  empty_container
  25             /*
  26                 This class represents always empty container,
  27                 containing elements of type CharT.
  28
  29                 It is supposed to be used in a const version only
  30             */
  31             template< typename CharT >
  32             struct empty_container
  33             {
  34                 typedef empty_container<CharT> type;
  35                 typedef CharT value_type;
  36                 typedef std::size_t size_type;
  37                 typedef std::ptrdiff_t difference_type;
  38                 typedef const value_type& reference;
  39                 typedef const value_type& const_reference;
  40                 typedef const value_type* iterator;
  41                 typedef const value_type* const_iterator;
  42
  43
  44                 // Operations
  45                 const_iterator begin() const
  46                 {
  47                     return reinterpret_cast<const_iterator>(0);
  48                 }
  49
  50                 const_iterator end() const
  51                 {
  52                     return reinterpret_cast<const_iterator>(0);
  53                 }
  54
  55                 bool empty() const
  56                 {
  57                     return false;
  58                 }
  59
  60                 size_type size() const
  61                 {
  62                     return 0;
  63                 }
  64             };
  65
  66 //  bounded copy algorithm  -----------------------------------------------//
  67
  68             // Bounded version of the std::copy algorithm
  69             template<typename InputIteratorT, typename OutputIteratorT>
  70             inline OutputIteratorT bounded_copy(
  71                 InputIteratorT First,
  72                 InputIteratorT Last,
  73                 OutputIteratorT DestFirst,
  74                 OutputIteratorT DestLast )
  75             {
  76                 InputIteratorT InputIt=First;
  77                 OutputIteratorT OutputIt=DestFirst;
  78                 for(; InputIt!=Last && OutputIt!=DestLast; InputIt++, OutputIt++ )
  79                 {
  80                     *OutputIt=*InputIt;
  81                 }
  82
  83                 return OutputIt;
  84             }
  85
  86 //  iterator range utilities -----------------------------------------//
  87
  88             // copy range functor
  89             template<
  90                 typename SeqT,
  91                 typename IteratorT=BOOST_STRING_TYPENAME SeqT::const_iterator >
  92             struct copy_iterator_rangeF :
  93                 public std::unary_function< iterator_range<IteratorT>, SeqT >
  94             {
  95                 SeqT operator()( const iterator_range<IteratorT>& Range ) const
  96                 {
  97                     return copy_range<SeqT>(Range);
  98                 }
  99             };
 100
 101         } // namespace detail
 102     } // namespace algorithm
 103 } // namespace boost
 104
 105
 106 #endif  // BOOST_STRING_UTIL_DETAIL_HPP