ceph/src/boost/libs/spirit/include/boost/spirit/home/support/iterators/detail/input_iterator_policy.hpp

   1 //  Copyright (c) 2001 Daniel C. Nuffer
   2 //  Copyright (c) 2001-2011 Hartmut Kaiser
   3 //
   4 //  Distributed under the Boost Software License, Version 1.0. (See accompanying
   5 //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6
   7 #if !defined(BOOST_SPIRIT_ITERATOR_INPUT_ITERATOR_POLICY_MAR_16_2007_1156AM)
   8 #define BOOST_SPIRIT_ITERATOR_INPUT_ITERATOR_POLICY_MAR_16_2007_1156AM
   9
  10 #include <boost/spirit/home/support/iterators/multi_pass_fwd.hpp>
  11 #include <boost/spirit/home/support/iterators/detail/multi_pass.hpp>
  12 #include <boost/detail/iterator.hpp> // for boost::detail::iterator_traits
  13 #include <boost/assert.hpp>
  14
  15 namespace boost { namespace spirit { namespace iterator_policies
  16 {
  17     namespace input_iterator_is_valid_test_
  18     {
  19         ///////////////////////////////////////////////////////////////////////
  20         template <typename Token>
  21         inline bool token_is_valid(Token const& c)
  22         {
  23             return c ? true : false;
  24         }
  25     }
  26
  27     ///////////////////////////////////////////////////////////////////////////
  28     //  class input_iterator
  29     //  Implementation of the InputPolicy used by multi_pass
  30     //
  31     //  The input_iterator encapsulates an input iterator of type T
  32     ///////////////////////////////////////////////////////////////////////////
  33     struct input_iterator
  34     {
  35         ///////////////////////////////////////////////////////////////////////
  36         template <typename T>
  37         class unique // : public detail::default_input_policy
  38         {
  39         private:
  40             typedef
  41                 typename boost::detail::iterator_traits<T>::value_type
  42             result_type;
  43
  44         public:
  45             typedef
  46                 typename boost::detail::iterator_traits<T>::difference_type
  47             difference_type;
  48             typedef
  49                 typename boost::detail::iterator_traits<T>::difference_type
  50             distance_type;
  51             typedef
  52                 typename boost::detail::iterator_traits<T>::pointer
  53             pointer;
  54             typedef
  55                 typename boost::detail::iterator_traits<T>::reference
  56             reference;
  57             typedef result_type value_type;
  58
  59         protected:
  60             unique() {}
  61             explicit unique(T x) {}
  62
  63             void swap(unique&) {}
  64
  65         public:
  66             template <typename MultiPass>
  67             static void destroy(MultiPass&) {}
  68
  69             template <typename MultiPass>
  70             static typename MultiPass::reference get_input(MultiPass& mp)
  71             {
  72                 return *mp.shared()->input_;
  73             }
  74
  75             template <typename MultiPass>
  76             static void advance_input(MultiPass& mp)
  77             {
  78                 ++mp.shared()->input_;
  79             }
  80
  81             // test, whether we reached the end of the underlying stream
  82             template <typename MultiPass>
  83             static bool input_at_eof(MultiPass const& mp)
  84             {
  85                 static T const end_iter;
  86                 return mp.shared()->input_ == end_iter;
  87             }
  88
  89             template <typename MultiPass>
  90             static bool input_is_valid(MultiPass const& mp, value_type const& t)
  91             {
  92                 using namespace input_iterator_is_valid_test_;
  93                 return token_is_valid(t);
  94             }
  95
  96             // no unique data elements
  97         };
  98
  99         ///////////////////////////////////////////////////////////////////////
 100         template <typename T>
 101         struct shared
 102         {
 103             explicit shared(T const& input) : input_(input) {}
 104
 105             T input_;
 106         };
 107     };
 108
 109 }}}
 110
 111 #endif