00001 // $Id: PacketParser.ih 1742 2010-11-04 14:51:56Z g0dil $ 00002 // 00003 // Copyright (C) 2007 00004 // Fraunhofer (FOKUS) 00005 // Competence Center NETwork research (NET), St. Augustin, GERMANY 00006 // Stefan Bund <g0dil@berlios.de> 00007 // 00008 // This program is free software; you can redistribute it and/or modify 00009 // it under the terms of the GNU General Public License as published by 00010 // the Free Software Foundation; either version 2 of the License, or 00011 // (at your option) any later version. 00012 // 00013 // This program is distributed in the hope that it will be useful, 00014 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00015 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00016 // GNU General Public License for more details. 00017 // 00018 // You should have received a copy of the GNU General Public License 00019 // along with this program; if not, write to the 00020 // Free Software Foundation, Inc., 00021 // 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 00022 00026 #ifndef IH_SENF_Packets_PacketParser_ 00027 #define IH_SENF_Packets_PacketParser_ 1 00028 00029 // Custom includes 00030 #include <senf/Utils/mpl.hh> 00031 00032 //-///////////////////////////////////////////////////////////////////////////////////////////////// 00033 00034 namespace senf { 00035 namespace detail { 00036 00037 // PLEASE don't add this to doxygen ... it just looks to weird and does not help ... 00038 00039 # ifndef DOXYGEN 00040 00041 // Use SFINAE to check, if Parser has an integer-valued init_bytes member. If not, 00042 // 'Parser_TakeNum<Parser::init_bytes>' fails and the overload is removed from the overload 00043 // set. 00044 template <class Parser> 00045 PacketParserBase::size_type packetParserSize( 00046 Parser p, int, senf::mpl::take_uint<Parser::init_bytes> * = 0); 00047 00048 // An ellipsis is always the worst match. A call 'packetParserSize(p,0) will prefer above 00049 // overload if that is not disabled by SFINAE. 00050 template <class Parser> 00051 PacketParserBase::size_type packetParserSize(Parser p, ...); 00052 00053 // Same as above: This overload is only enabled, if Parser has an integer values 'init_bytes' 00054 // member. 00055 template <class Parser> 00056 senf::mpl::rv<0> ParserInitBytes_Choose_(senf::mpl::take_uint<Parser::init_bytes> *); 00057 00058 template <class Parser> 00059 senf::mpl::rv<1> ParserInitBytes_Choose_(...); 00060 00061 // This version of ParserInitBytes_Choose uses 'Parser::init_bytes' to provide 'value' (via 00062 // 'boost::integral_constant') 00063 template <class Parser, unsigned _> 00064 struct ParserInitBytes_Choose 00065 : public boost::integral_constant<PacketParserBase::size_type, Parser::init_bytes> {}; 00066 // ^^-- g++ error signaled here: 00067 // error: 'fixed_bytes' is not a member of 'some-class-name' 00068 // 00069 // The 'some-class-name' class (as given in the error message) does not seem to be a parser at 00070 // all (it has neither a 'fixed_bytes' nor an 'init_bytes' member). 00071 // 00072 // Either 'some-class-name' is not the class you wanted to use (it really is no parser) or you 00073 // left out either 'init_bytes' or 'fixed_bytes' when defining the parser. This will also 00074 // happen, if you forget to call 'SENF_PARSER_FINALIZE()' when defining a composite parser. 00075 //-///////////////////////////////////////////////////////////////////////////////////////////// 00076 00077 // If Parser::init_bytes is not defined, this specialization is chosen which instead uses 00078 // 'Parser::fixed_bytes' 00079 template <class Parser> 00080 struct ParserInitBytes_Choose<Parser, 1> 00081 : public boost::integral_constant<PacketParserBase::size_type, Parser::fixed_bytes> {}; 00082 00083 template <class Parser> 00084 struct ParserInitBytes 00085 : public ParserInitBytes_Choose<Parser,SENF_MPL_RV(ParserInitBytes_Choose_<Parser>(0))> {}; 00086 00087 template <class Parser, unsigned _> 00088 struct ParserIsFixed_Choose 00089 : public boost::false_type {}; 00090 00091 template <class Parser> 00092 struct ParserIsFixed_Choose<Parser, 1> 00093 : public boost::true_type {}; 00094 00095 template <class Parser> 00096 struct ParserIsFixed 00097 : public ParserIsFixed_Choose<Parser,SENF_MPL_RV(ParserInitBytes_Choose_<Parser>(0))> {}; 00098 00099 # endif 00100 00101 }} 00102 00103 //-///////////////////////////////////////////////////////////////////////////////////////////////// 00104 #endif 00105 00106 00107 // Local Variables: 00108 // mode: c++ 00109 // fill-column: 100 00110 // c-file-style: "senf" 00111 // indent-tabs-mode: nil 00112 // ispell-local-dictionary: "american" 00113 // compile-command: "scons -u test" 00114 // comment-column: 40 00115 // End: