ceph/src/boost/boost/spirit/home/support/iterators/detail/buf_id_check_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_BUF_ID_CHECK_POLICY_MAR_16_2007_1108AM)
   8 #define BOOST_SPIRIT_ITERATOR_BUF_ID_CHECK_POLICY_MAR_16_2007_1108AM
   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/config.hpp>
  13 #include <boost/throw_exception.hpp>
  14 #include <exception>    // for std::exception
  15
  16 namespace boost { namespace spirit { namespace iterator_policies
  17 {
  18     ///////////////////////////////////////////////////////////////////////////
  19     //  class illegal_backtracking
  20     //  thrown by buf_id_check CheckingPolicy if an instance of an iterator is
  21     //  used after another one has invalidated the queue
  22     ///////////////////////////////////////////////////////////////////////////
  23     class BOOST_SYMBOL_VISIBLE illegal_backtracking : public std::exception
  24     {
  25     public:
  26         illegal_backtracking() BOOST_NOEXCEPT_OR_NOTHROW {}
  27         ~illegal_backtracking() BOOST_NOEXCEPT_OR_NOTHROW {}
  28
  29         char const* what() const BOOST_NOEXCEPT_OR_NOTHROW
  30         {
  31             return "boost::spirit::multi_pass::illegal_backtracking";
  32         }
  33     };
  34
  35     ///////////////////////////////////////////////////////////////////////////////
  36     //  class buf_id_check
  37     //  Implementation of the CheckingPolicy used by multi_pass
  38     //  This policy is most effective when used together with the std_deque
  39     //  StoragePolicy.
  40     //
  41     //  If used with the fixed_size_queue StoragePolicy, it will not detect
  42     //  iterator dereferences that are out of the range of the queue.
  43     ///////////////////////////////////////////////////////////////////////////////
  44     struct buf_id_check
  45     {
  46         ///////////////////////////////////////////////////////////////////////
  47         struct unique //: detail::default_checking_policy
  48         {
  49             unique() : buf_id(0) {}
  50             unique(unique const& x) : buf_id(x.buf_id) {}
  51
  52             void swap(unique& x)
  53             {
  54                 boost::swap(buf_id, x.buf_id);
  55             }
  56
  57             // called to verify that everything is ok.
  58             template <typename MultiPass>
  59             static void docheck(MultiPass const& mp)
  60             {
  61                 if (mp.buf_id != mp.shared()->shared_buf_id)
  62                     boost::throw_exception(illegal_backtracking());
  63             }
  64
  65             // called from multi_pass::clear_queue, so we can increment the count
  66             template <typename MultiPass>
  67             static void clear_queue(MultiPass& mp)
  68             {
  69                 ++mp.shared()->shared_buf_id;
  70                 ++mp.buf_id;
  71             }
  72
  73             template <typename MultiPass>
  74             static void destroy(MultiPass&) {}
  75
  76         protected:
  77             unsigned long buf_id;
  78         };
  79
  80         ///////////////////////////////////////////////////////////////////////
  81         struct shared
  82         {
  83             shared() : shared_buf_id(0) {}
  84             unsigned long shared_buf_id;
  85         };
  86     };
  87
  88 }}}
  89
  90 #endif