September 2006 - Boost-users

Re: [Boost-users] [string_algo] wildcard support?
by james.jones＠firstinvestors.com 08 Sep '06

08 Sep '06

From: "Richard Dingwall" <rdingwall(a)gmail.com> > Cheers. I was rather hoping not to have to use regular expressions; > they're kinda beyond the intended users of my program (it's for a > user-defined filter function, and I don't expect them to be familiar > with regex syntax). > > I cheaped out and used an old C wildcmp(wild.c_str(), text.c_str()) > method instead. Just because YOU use regex internally doesn't mean to have to expose full regex capabilities to the users. You could, for example, use a */? wildcard arrangement like DOS or bash shell uses, use a regex to verify that the wildcard pattern was valid, and then translate this into a real regex for the internal search. Use Boost!! Don't cheap-out. :) - James Jones Administrative Data Mgmt. Webmaster 375 Raritan Center Pkwy, Suite A Data Architect Edison, NJ 08837

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[serialization] different behaviour between xml_wiarchive and binary_wiarchive
by Oliver Mutz 08 Sep '06

08 Sep '06

In my application I'm trying to serialize data alternatively to xml_wiarchive or binary_wiarchive. Writing and reading XML works without any problems. Binary writing seems to work too, but reading the file throws an exception with exception_code 'unregistered_class'. What I do is reading the XML data, writing binary and reading binary back in. I thought there should be no difference which kind of archive I use. Am I missing a point? I would be thankful for any hint. I know that it is hard to guess where the problem might be without seeing any code, but I by now I was not able to create some simple example which shows the same behaviour. I'm using Windows XP (SP2) with MSVC 8.0. Thanks. Oliver

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How to use bind/lambda in a conditional for_each?
by Baranowski, Daniel 08 Sep '06

08 Sep '06

Hey all! I've really enjoyed using boost::bind for calling member functions and such. I wish I had found this earlier! Anyhow, I'm trying to write for_each statement that only passes the object to a function if certain conditions are met. Unfortunately, I'm not well versed enough in boost::bind (and I've never used the lambda library) so I'm not sure how to do this! Can someone lend me a hand? I couldn't find anything in the mail archives. If I were writing a regular for-loop, this is how it would look: vector<MyObjClass> myVector; myVector.push_back(MyObjClass(2)); myVector.push_back(MyObjClass(3)); myVector.push_back(MyObjClass(3)); myVector.push_back(MyObjClass(5)); myVector.push_back(MyObjClass(6)); vector<MyObjClass>::iterator end = myVector.end(); vector<MyObjClass>::iterator itr; for(itr = myVector.begin(); itr != end; ++itr) { if((*itr).GetValue() == 3) ProcessingFunction(*itr); } And here's the for_each that just passes every object into the processing function: // From inside a function in a class called ThisClass vector<MyObjClass> myVector; myVector.push_back(MyObjClass(2)); myVector.push_back(MyObjClass(3)); myVector.push_back(MyObjClass(3)); myVector.push_back(MyObjClass(5)); myVector.push_back(MyObjClass(6)); vector<MyObjClass>::iterator begin = myVector.begin(); vector<MyObjClass>::iterator end = myVector.end(); for_each(begin, end, boost::bind(&ThisClass::ProcessingFunction, this, _1)); So I guess the question is, how do I add the condition into the for_each? I know there's got to be a way! Thanks for any help! Daniel ********************************************************************************************** Disclaimer - This email and any files transmitted with it are proprietary and may contain privileged or copyright information. You must not present this message to another party without gaining permission from the sender. If you are not the intended recipient you must not copy, distribute or use this email or the information contained in it for any purpose other than to notify us. If you have received this message in error, please notify the sender immediately, and delete this email from your system. We do not guarantee that this material is free from viruses or any other defects although due care has been taken to minimize the risk. eSafe scanned this email for viruses, vandals and malicious contentAny views expressed in this message are those of the individual sender, except where the sender specifically states them to be the views of LSI. **********************************************************************************************

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[Signals] Relationships to other libraries and terms
by Scott Meyers 08 Sep '06

08 Sep '06

I've been trying to make sense of Boost.Signals, especially in terms of some other libraries I'm familiar with. Part of the problem is terminology, I think, e.g., callbacks, slots, and delegates (as in .NET, but also as used by some for bound member function pointers (e.g.,http://www.codeproject.com/cpp/FastDelegate.asp)) I'm hoping people will take a look at what follows, correct any errors they see, and maybe lend additional insight so that my understanding will be improved. We start with "callable entities" -- things that can be called, e.g., function pointers, function objects, bound member functions, etc. As I understand it: - A callback (function or object) is a callable entity - A slot in Boost.Signals is a callable entity - boost::bind and boost::lambda create callable entities. - A boost::function object stores a callable entity. We also have collections of callable entities: - A .NET delegate is a collection of 0 or more callable entities with a given signature. - A signal in Boost.Signals is a collection of 0 or more callable entities with signatures compatible with a given signature. Objects of these collection types are also callable entities: - When a Boost.Signals signal or a .NET delegate is called, it invokes the callable entities it contains. Is that correct? Also, does anybody know where the name "slot" comes from in this context? I've found this term to be a stumbling block for trying to understand this stuff. Thanks, Scott

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[asio] tcp::socket state query?
by Rod Morison 08 Sep '06

08 Sep '06

Is there way to query the local status of a socket in asio? Or, is there another technique for state & error management? For example, something lick the TcpSocket state in Qt v4. I.e., AbstractSocket::UnconnectedState 0 The socket is not connected. QAbstractSocket::HostLookupState 1 The socket is performing a host name lookup. QAbstractSocket::ConnectingState 2 The socket has started establishing a connection. QAbstractSocket::ConnectedState 3 A connection is established. QAbstractSocket::BoundState 4 The socket is bound to an address and port (for servers). QAbstractSocket::ClosingState 6 The socket is about to close (data may still be waiting to be written). QAbstractSocket::ListeningState 5 For internal use only. (from http://doc.trolltech.com/4.2/qabstractsocket.html#SocketState-enum) Here's why I'm asking: I'm looking at the chat_client.cpp example.The socket is connected via async_connect in the chat_client constructor. If the first resolved endpoint fails to connect the handler tries an async_connect with the next endpoint. First question: Are the async requests initiated under an io_servce (and executed by the run() method) queued in the order they are called via async_xxx calls? (I'm assuming/hoping that's a yes.) So the issue I have with the chat_client design is as follows: because iterating the endpoint list (to connect the socket) is in a handler, what if another socket operation slipped in ahead of that handler, say a write (assuming the first endpoint failed)? I'd want the do_write() function to be able to check the socket state. I can do the state control myself via the handlers and a class state variable, but is there a better way? (Similarly, this app can happily go writing to an unconnected socket--I realize it's a sample, not production code, but I'm thinking through my _real_ app here.) Hope this makes sense, Rod

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[iostreams] Building with vacpp toolset
by Patrik Jonsson 07 Sep '06

07 Sep '06

Hi I'm trying to build boost with the vacpp (IBM Visual Age C++) compilers, but the iostreams library won't build. It appears to be missing include files zlib.h and bzlib.h: xlC -c -I/project/projectdirs/mp363/sunrise/pbuild/boost_1_33_1 -qNOOPTimize -qnoinline -g -qfullpath -qnotempinc -qfuncsect -qeh -qrtti -I"bin/boost/libs/iostreams/build" -I"/project/projectdirs/mp363/sunrise/pbuild/boost_1_33_1" -I"/project/projectdirs/mp363/sunrise/pbuild/boost_1_33_1" -o "bin/boost/libs/iostreams/build/libboost_iostreams.a/vacpp/debug/bzip2.o" "/project/projectdirs/mp363/sunrise/pbuild/boost_1_33_1/libs/iostreams/build/../src/bzip2.cpp" ...failed xlc-C++-action bin/boost/libs/iostreams/build/libboost_iostreams.a/vacpp/debug/bzip2.o... xlc-C++-action bin/boost/libs/iostreams/build/libboost_iostreams.a/vacpp/debug/zlib.o "/project/projectdirs/mp363/sunrise/pbuild/boost_1_33_1/libs/iostreams/build/../src/zlib.cpp", line 18.10: 1540-0836 (S) The #include file "zlib.h" is not found. xlC -c -I/project/projectdirs/mp363/sunrise/pbuild/boost_1_33_1 -qNOOPTimize -qnoinline -g -qfullpath -qnotempinc -qfuncsect -qeh -qrtti -I"bin/boost/libs/iostreams/build" -I"/project/projectdirs/mp363/sunrise/pbuild/boost_1_33_1" -I"/project/projectdirs/mp363/sunrise/pbuild/boost_1_33_1" -o "bin/boost/libs/iostreams/build/libboost_iostreams.a/vacpp/debug/zlib.o" "/project/projectdirs/mp363/sunrise/pbuild/boost_1_33_1/libs/iostreams/build/../src/zlib.cpp" ...failed xlc-C++-action bin/boost/libs/iostreams/build/libboost_iostreams.a/vacpp/debug/zlib.o... ...skipped <@boost!libs!iostreams!build/libboost_iostreams.a/vacpp/debug>libboost_iostreams-xlc-d-1_33_1.a for lack of <@boost!libs!iostreams!build/libboost_iostreams.a/vacpp/debug>libboost_iostreams-xlc-d-1_33_1.a(bzip2.o)... ...skipped <@boost!lib>libboost_iostreams-xlc-d-1_33_1.a for lack of <@boost!libs!iostreams!build/libboost_iostreams.a/vacpp/debug>libboost_iostreams-xlc-d-1_33_1.a... xlc-C++-action bin/boost/libs/iostreams/build/libboost_iostreams.a/vacpp/debug/threading-multi/bzip2.o "/project/projectdirs/mp363/sunrise/pbuild/boost_1_33_1/libs/iostreams/build/../src/bzip2.cpp", line 18.10: 1540-0836 (S) The #include file "bzlib.h" is not found. This is with xlC 8.0.0.0 on an IBM SP5 running AIX5. Any hints for resolving this would be appreciated. Thank you, /Patrik Jonsson

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[wave] Building with vacpp toolset
by Patrik Jonsson 07 Sep '06

07 Sep '06

Hi I'm trying to build boost with the vacpp (IBM Visual Age C++) compilers, but the wave library won't build: xlc-C++-action bin/boost/libs/wave/build/libboost_wave.a/vacpp/debug/instantiate_cpp_grammar.o "/project/projectdirs/mp363/sunrise/pbuild/boost_1_33_1/boost/wave/cpplexer/cpp_lex_iterator.hpp", line 53.13: 1540-0038 (S) The name "typename TokenT::position_type" is not a type. <see end of message for the rest of the error, for that file> This is with xlC 8.0.0.0 on an IBM SP5 running AIX5. Any hints for resolving this would be appreciated. Thank you, /Patrik Jonsson ... "/project/projectdirs/mp363/sunrise/pbuild/boost_1_33_1/boost/wave/util/functor_input.hpp", line 43.26: 1540-0700 (I) The previous message was produced while processing "class boost::wave::cpplexer::impl::lex_iterator_functor_shim<boost::wave::cpplexer::lex_token<boost::wave::util::file_position<boost::wave::util::flex_string<char,std::char_traits<char>,std::allocator<char>,boost::wave::util::CowString<boost::wave::util::AllocatorStringStorage<char,std::allocator<char> >,char *> > > > >". "/project/projectdirs/mp363/sunrise/pbuild/boost_1_33_1/boost/wave/util/functor_input.hpp", line 41.11: 1540-0700 (I) The previous message was produced while processing "class boost::wave::util::functor_input::inner<boost::wave::cpplexer::impl::lex_iterator_functor_shim<boost::wave::cpplexer::lex_token<boost::wave::util::file_position<boost::wave::util::flex_string<char,std::char_traits<char>,std::allocator<char>,boost::wave::util::CowString<boost::wave::util::AllocatorStringStorage<char,std::allocator<char> >,char *> > > > > >". "/project/projectdirs/mp363/sunrise/pbuild/boost_1_33_1/boost/spirit/iterator/multi_pass.hpp", line 805.7: 1540-0700 (I) The previous message was produced while processing "class boost::spirit::multi_pass<boost::wave::cpplexer::impl::lex_iterator_functor_shim<boost::wave::cpplexer::lex_token<boost::wave::util::file_position<boost::wave::util::flex_string<char,std::char_traits<char>,std::allocator<char>,boost::wave::util::CowString<boost::wave::util::AllocatorStringStorage<char,std::allocator<char> >,char *> > > > >,boost::wave::util::functor_input,boost::spirit::multi_pass_policies::ref_counted,boost::spi...". "/project/projectdirs/mp363/sunrise/pbuild/boost_1_33_1/boost/wave/cpplexer/cpp_lex_iterator.hpp", line 118.7: 1540-0700 (I) The previous message was produced while processing "class boost::wave::cpplexer::lex_iterator<boost::wave::cpplexer::lex_token<boost::wave::util::file_position<boost::wave::util::flex_string<char,std::char_traits<char>,std::allocator<char>,boost::wave::util::CowString<boost::wave::util::AllocatorStringStorage<char,std::allocator<char> >,char *> > > > >". "/project/projectdirs/mp363/sunrise/pbuild/boost_1_33_1/boost/wave/grammars/cpp_grammar_gen.hpp", line 68.8: 1540-0700 (I) The previous message was produced while processing "struct boost::wave::grammars::cpp_grammar_gen<boost::wave::cpplexer::lex_iterator<boost::wave::cpplexer::lex_token<boost::wave::util::file_position<boost::wave::util::flex_string<char,std::char_traits<char>,std::allocator<char>,boost::wave::util::CowString<boost::wave::util::AllocatorStringStorage<char,std::allocator<char> >,char *> > > > > >".

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ptr_container compiles slow
by LionAM 07 Sep '06

07 Sep '06

Hello! I'm using Visual C++ 6 (for an MFC-Project). When I include <boost\ptr_container\ptr_vector.hpp> in an Sourcefile, it takes over 11 seconds to compile (without less than 1 second!) If I really wanted to use ptr_containers in my Project, I would have to include it in many files. But then compilation takes too long... Are there any possibilities to speed this up? Alex -- View this message in context: http://www.nabble.com/ptr_container-compiles-slow-tf2225929.html#a6168364 Sent from the Boost - Users forum at Nabble.com.

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[serialization] Newbie question on serializing a derived class
by David Pettigrew 07 Sep '06

07 Sep '06

I have a class that is derived from a GUI framework class and it seems like the serialization library will attempt to serialize the parent class but I don't own that classes code. I get an error "'GUIWidget::GUIWidget' : cannot access private member declared in class 'GUIWidget'". I do not know why it is looking in the parent class since I do not do anything with the base_object. Is there a way to get around this issue? I am doing somethine wrong? Here is the code, #include <boost/archive/tmpdir.hpp> #include <boost/archive/text_wiarchive.hpp> #include <boost/archive/text_woarchive.hpp> #include <boost/serialization/vector.hpp> #include <fstream> #include <iostream> namespace boost { namespace serialization { class access; } } class MyClass: public GUIWidget { public: MyClass(); ~MyClass(); private: std::vector<LSLogEntry> m_logEntryList; // LSLogEntry has wstring members. friend class boost::serialization::access; // When the class Archive corresponds to an output archive, the // & operator is defined similar to <<. Likewise, when the class Archive // is a type of input archive the & operator is defined similar to >>. template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & m_logEntryList; } }; // free functions void save(const MyClass& eftw, const char * filename) { std::string fullPath(boost::archive::tmpdir()); fullPath += filename; // save the schedule try { // make an archive std::wofstream ofs(fullPath.c_str()); boost::archive::text_woarchive oa(ofs); oa << eftw; } catch (boost::archive::archive_exception e) { wcout << e.what(); } } void load(MyClass& eftw, const char * filename) { std::string fullPath(boost::archive::tmpdir()); fullPath += filename; // Restore the data try { // open the archive std::wifstream ifs(fullPath.c_str()); boost::archive::text_wiarchive ia(ifs); // restore from the archive ia >> eftw; } catch (boost::archive::archive_exception e) { wcout << e.what(); } } Thanks, David

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Why am I not hearing that my edge has already been added?
by Eric Fowler 07 Sep '06

07 Sep '06

I am writing a simple graph app. The edges have an unsigned integer property that is incremented every time I "add" an edge from one given node to another, thus, any given edge has an "instance" of at least one, but if there are, say, three edges from node A to node B, edge A->B has nInstances == 3. To do this I would like to attempt to add an edge between nodes, and if the edge has already been added, just bump the counter for that edge, otherwise, set the counter to 1. My basic approach is to call tie(edge_iter, boolflag) = add_edge(v0, v1, graph). If boolvar is set to false then the edge already was in the graph. The problem is that add_edge() never clears boolvar - it is always true, even when I coerce redundant edges, as in the following code: #include "stdafx.h" #include <boost/graph/adjacency_list.hpp> #include <boost/property_map.hpp> using namespace boost; using namespace std; //Don't worry about the vertex property, it is irrelevant ... struct vertex_char_t { typedef vertex_property_tag kind; }; typedef property<vertex_char_t, char> VertexCharProperty; typedef adjacency_list<vecS, vecS, directedS, VertexCharProperty> Graph; int _tmain(int argc, _TCHAR* argv[]) { Graph g(256); property_map<Graph, vertex_char_t>::type vert_char = get(vertex_char_t(), g); typedef graph_traits<Graph>::vertex_descriptor Vertex; Vertex va, vb; typedef graph_traits<Graph>::edge_descriptor Edge; Edge ei; bool bNotPresent = false; for(unsigned i = 0; i < 256; ++i) { va = vertex(0, g); vb = vertex(1, g); /* ***ADD REDUNDANT EDGES BETWEEN NODES 0, 1 */ tie(ei, bNotPresent) = add_edge(va, vb, g); //BUT MY FLAG ALWAYS == true, why? if(!bNotPresent) break; } return 0; }

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