ceph/src/boost/boost/spirit/home/classic/utility/flush_multi_pass.hpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2003 Daniel Nuffer
   3     http://spirit.sourceforge.net/
   4
   5   Distributed under the Boost Software License, Version 1.0. (See accompanying
   6   file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   7 =============================================================================*/
   8 #ifndef BOOST_SPIRIT_FLUSH_MULTI_PASS_HPP
   9 #define BOOST_SPIRIT_FLUSH_MULTI_PASS_HPP
  10
  11 ///////////////////////////////////////////////////////////////////////////////
  12 #include <boost/spirit/home/classic/namespace.hpp>
  13 #include <boost/spirit/home/classic/core.hpp>
  14 #include <boost/spirit/home/classic/iterator/multi_pass.hpp>
  15
  16 ///////////////////////////////////////////////////////////////////////////////
  17 namespace boost { namespace spirit {
  18
  19 BOOST_SPIRIT_CLASSIC_NAMESPACE_BEGIN
  20
  21     namespace impl {
  22
  23         template <typename T>
  24         void flush_iterator(T &) {}
  25
  26         template <typename T1, typename T2, typename T3, typename T4>
  27         void flush_iterator(BOOST_SPIRIT_CLASSIC_NS::multi_pass<
  28             T1, T2, T3, T4, BOOST_SPIRIT_CLASSIC_NS::multi_pass_policies::std_deque> &i)
  29         {
  30             i.clear_queue();
  31         }
  32
  33     }   // namespace impl
  34
  35     ///////////////////////////////////////////////////////////////////////////
  36     //
  37     //  flush_multi_pass_parser
  38     //
  39     //      The flush_multi_pass_parser flushes an underlying
  40     //      multi_pass_iterator during the normal parsing process. This may
  41     //      be used at certain points during the parsing process, when it is
  42     //      clear, that no backtracking is needed anymore and the input
  43     //      gathered so far may be discarded.
  44     //
  45     ///////////////////////////////////////////////////////////////////////////
  46     class flush_multi_pass_parser
  47     :   public parser<flush_multi_pass_parser>
  48     {
  49     public:
  50         typedef flush_multi_pass_parser this_t;
  51
  52         template <typename ScannerT>
  53         typename parser_result<this_t, ScannerT>::type
  54         parse(ScannerT const& scan) const
  55         {
  56             impl::flush_iterator(scan.first);
  57             return scan.empty_match();
  58         }
  59     };
  60
  61     ///////////////////////////////////////////////////////////////////////////
  62     //
  63     //  predefined flush_multi_pass_p object
  64     //
  65     //      This object should may used to flush a multi_pass_iterator along
  66     //      the way during the normal parsing process.
  67     //
  68     ///////////////////////////////////////////////////////////////////////////
  69
  70     flush_multi_pass_parser const
  71         flush_multi_pass_p = flush_multi_pass_parser();
  72
  73 BOOST_SPIRIT_CLASSIC_NAMESPACE_END
  74
  75 }} // namespace BOOST_SPIRIT_CLASSIC_NS
  76
  77 #endif // BOOST_SPIRIT_FLUSH_MULTI_PASS_HPP