- Boost-users - lists.boost.org

Re: [Boost-users] Simple fast parsing
by Cory Nelson 21 Jun '09

21 Jun '09

Just write the parser to use forward iterators, then it is trivial to support any source you have. -----Original Message----- From: Christopher Jefferson <chris(a)bubblescope.net> Sent: Sunday, June 21, 2009 1:28 PM To: boost-users(a)lists.boost.org Subject: [Boost-users] Simple fast parsing I am currently using in a project a custom-writen recursive-decent parser, which uses an filtering_istream so I can support compressed input. The only functionality used is peekchar, getchar and integer extraction with 'stream >> i'. I am finding that C++ streams, particularly when it comes to integer extraction, are giving terrible performance. In a small test, uncompressing to a buffer and then writing a simple custom reader on that memory buffer gives 10x performance. I would perfer not to write and support such a tool if possible. Is there a boost library which easily supports a parser with 1 character lookahead and simple things like integer extraction? Looking at the documentation, Boost::Spirit seems like a very big hammer to crack this quite small nut, and it is unclear to me how well it would fit into an existing recursive decent parser. Has anyone ever used it as such? Is there a simple alternative? Chris _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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Build error
by David Doria 21 Jun '09

21 Jun '09

I have been unable to build boost-trunk for a while now because of this error: [ 58%] Building CXX object libs/accumulators/example/CMakeFiles/accumulators-accumulators_example.dir/main.cpp.o /home/doriad/src/boost-trunk/boost/accumulators/statistics_fwd.hpp: In function ‘void example1()’: /home/doriad/src/boost-trunk/boost/accumulators/statistics_fwd.hpp:87: error: ‘template<int N> struct boost::accumulators::tag::moment’ is not a function, /home/doriad/src/boost-trunk/boost/accumulators/statistics/moment.hpp:104: error: conflict with ‘template<int T2, class Arg1, class A0, class A1, class A2, class A3, class A4, class A5, class A6, class A7, class A8, class A9, class A10, class A11, class A12, class A13, class A14> typename boost::accumulators::detail::extractor_result<Arg1, boost::accumulators::tag::moment<T2> >::type boost::accumulators::extract::moment(const Arg1&, const A0&, const A1&, const A2&, const A3&, const A4&, const A5&, const A6&, const A7&, const A8&, const A9&, const A10&, const A11&, const A12&, const A13&, const A14&)’ /home/doriad/src/boost-trunk/libs/accumulators/example/main.cpp:63: error: in call to ‘moment’ make[2]: *** [libs/accumulators/example/CMakeFiles/accumulators-accumulators_example.dir/main.cpp.o] Error 1 make[1]: *** [libs/accumulators/example/CMakeFiles/accumulators-accumulators_example.dir/all] Error 2 make: *** [all] Error 2 Is anyone else having this problem? Thanks, David

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Re: [Boost-users] [BGL] Segmentation fault
by Caligula 21 Jun '09

21 Jun '09

Steve, I put the relevant files on http://www.tinyurl.com/nwj5du . There is a readme file with explanation. It should be pretty simple to get running. Thanks Caligula Maybe a dumb question, but what is the vis object? The visitor object . See http://tinyurl.com/nutww8 . The boost: bgl depth first search example. Could you post a complete compilable example? It's a little hard to figure out exactly what you're doing. In Christ, Steven Watanabe _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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[Boost.Test] valgrind complains about invalid reads
by Peter Klotz 20 Jun '09

20 Jun '09

Boost 1.37.0, Linux, x86_64, gcc 4.1: Valgrind 3.3.1 complains when running this simple test: #define BOOST_TEST_MAIN #include <boost/test/unit_test.hpp> BOOST_AUTO_TEST_CASE( test1 ) { BOOST_CHECK( 1 == 1 ); } The valgrind messages: ==1836== Memcheck, a memory error detector. ==1836== Copyright (C) 2002-2007, and GNU GPL'd, by Julian Seward et al. ==1836== Using LibVEX rev 1854, a library for dynamic binary translation. ==1836== Copyright (C) 2004-2007, and GNU GPL'd, by OpenWorks LLP. ==1836== Using valgrind-3.3.1, a dynamic binary instrumentation framework. ==1836== Copyright (C) 2000-2007, and GNU GPL'd, by Julian Seward et al. ==1836== For more details, rerun with: -v ==1836== Running 1 test case... *** No errors detected ==1836== Invalid read of size 8 ==1836== at 0x41E41C: __tcf_1 (in RegressionTest) ==1836== by 0x3830632FA4: exit (in /lib64/libc-2.5.so) ==1836== by 0x383061D8BA: (below main) (in /lib64/libc-2.5.so) ==1836== Address 0x4c1ade0 is 40 bytes inside a block of size 48 free'd ==1836== at 0x4A0555C: operator delete(void*) (vg_replace_malloc.c:342) ==1836== by 0x42024C: std::_Rb_tree<unsigned long, std::pair<unsigned long const, boost::unit_test::test_unit*>, std::_Select1st<std::pair<unsigned long const, boost::unit_test::test_unit*> >, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, boost::unit_test::test_unit*> > >::erase(unsigned long const&) (in RegressionTest) ==1836== by 0x417C11: boost::unit_test::test_unit::~test_unit() (in RegressionTest) ==1836== by 0x41E41B: __tcf_1 (in RegressionTest) ==1836== by 0x3830632FA4: exit (in /lib64/libc-2.5.so) ==1836== by 0x383061D8BA: (below main) (in /lib64/libc-2.5.so) ==1836== ==1836== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 5 from 1) ==1836== malloc/free: in use at exit: 0 bytes in 0 blocks. ==1836== malloc/free: 89 allocs, 89 frees, 38,935 bytes allocated. ==1836== For counts of detected errors, rerun with: -v ==1836== All heap blocks were freed -- no leaks are possible. I was not able to figure out what valgrind is really complaining about. The internal map of test units holds two entries. One corresponds to my BOOST_AUTO_TEST_CASE call (id=1), the other one seems to be used internally (id=65536). Both are properly erased in deregister_test_unit() which is called by ~test_unit(). Maybe someone with a little bit more insight into Boost.Test is willing to look at this. Regards, Peter.

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Segmentation fault
by caligulaemperorofrome＠yahoo.com 20 Jun '09

20 Jun '09

Trying to use bundled properties like so. typedef std::string Colour; struct edge_properties { string eName; set< Colour > Colours; }; Then the following works OUTSIDE the vis object. graph_t::edge_descriptor e = *edges(g).first; g[e].Colours.insert("5ty"); g[e].Colours.insert("6"); g[e].Colours.insert("7"); set<Colour> set(g[e].Colours); for(std::set<Colour>::iterator si = set.begin(); si != set.end(); si++) std::cout << *si << " "; But if I try to use edge property.Colours INSIDE the vis object (using maps or not) like so. typedef set< string > Set; for(colour_iter=Colour.begin(); colour_iter != Colour.end(); ++colour_iter) { //Set & set = get(m_eColours_map, e); get(m_eColours_map, e).insert( *colour_iter ); //set.insert( *colour_iter ); //g[e].Colours; //g[e].Colours.insert("Green"); //g[e].Colours.insert(*colour_iter); //g[e].Colours.insert("5"); //g[e].Colours.end(); } It compiles but gives Segmentation fault no matter what I try. Im beginning to think that set< string > will not work inside the vis object. If thats true I'll have to rewrite a major part of my program, but I hope not. Using : BOOST_LIB_VERSION "1_36" Thanks Caligula

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[BGL] IncidenceGraph and out_edges
by Christian Bähnisch 20 Jun '09

20 Jun '09

Hello, I do a repost here because of a silly subject copy and paste error of me, sorry for that! The text of my original message is: I'm trying to implement the IncidenceGraph concept for an non-BGL undirected graph like datastructure. Following the boost documentation the target function used with edges from out_edges(u,g) must give vertices != u. Can somebody please explain me why this requirement is in BGL! I think it can make the adaption very difficult as it requieres to artificially orientate undirected edges for each call to out_edges. Any help would be much appreciated! best regards, Chris

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[Q] serializing Database Null values (design question)
by V S P 20 Jun '09

20 Jun '09

I have my CPP ORM pretty much working (so that I can read data from the database and serialize it with boost serialize) in generic manner. There is an issue however with 'Nulls' that possibly exist in the database. I use underneath OTL c++ db library and it has a 'null indicator' like many db libraries do. So if I see a value where null indicator is set to true, should I serialize it out and if yes -- is there something like 'NaN' for all the different value types defined? or should I skip serializing that specific field? that would I think work (unless I do not foresee something) -- in the sense that the field will not get loaded back by 'unserialize' and therefore will contain the value assigned in its constructor. just wanted to hear opinions on this. thank you -- V S P toreason(a)fastmail.fm -- http://www.fastmail.fm - mmm... Fastmail...

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[Q] reading back serialized Collection of shared_ptr
by V S P 20 Jun '09

20 Jun '09

I made may be a little more headways since my previous question and now have an xml archive that appears to 'denote' the shared pointers (see below) To do this I found and used boost template function specifically for shared pointers -- a data member of myclass inheritin from std::multiset -- TRow is the Value type of the multiset that implements 'serialize' method -- -- struct { template <typename Archive> void serialize (Archive& ar, const unsigned int version)const { for(tThisClassConstIterator it=this->begin(); it!=this->end(); ++it) { boost::serialization::save<Archive,typename TRow>(ar,*it,version); } } tTEST_TB3 now however I do not understand how to 'deserialize this' The basic call to void load_table (tTEST_TB3& t, const char * filename) { // open the archive std::ifstream ifs(filename); assert(ifs.good()); boost::archive::xml_iarchive ia(ifs); ia >> BOOST_SERIALIZATION_NVP(t); } does not even compile, I suspect it is because when this 'serialize' function on tTEST_TB3 is called, now the boost::serialization::save<Archive,typename TRow>(ar,*it,version); is NOT valid, because the ar is of type iarchive, and save function on the shared_ptr is not defined for 'iarchive', only for oarchive. So there is another function in the same boost header file ( #include <boost/serialization/shared_ptr.hpp> ) that defines a 'load' function for the shared ptr However -- what I do not undestand is how to invoke this function it seems like I have to iterate through every entry in the archive and then call load to read it into a shared ptr? That seems to be contrary to all the other mechanism supported by the Serialization library. The basic examples just say that I can take a container and just shift it in (or out) of Archiver -- but that does not work if the container is of shared pointers. That's why I went the route of iterating through every element of the container to serialize, and not do not undestand how to load it back. So I need some help (I can provide the complete example if needed) thank you in advance ---------- <?xml version="1.0" encoding="UTF-8" standalone="yes" ?> <!DOCTYPE boost_serialization> <boost_serialization signature="serialization::archive" version="5"> <t class_id="0" tracking_level="0" version="0"> <px class_id="1" tracking_level="1" version="0" object_id="_0"> <otrq_prov_id>1245439719</otrq_prov_id> <clnt_dbid>1245439719</clnt_dbid> <mydate>6/19/2009 15:28:39</mydate> <amount>33222112121.212000</amount> </px> <px class_id_reference="1" object_id="_1"> <otrq_prov_id>1245439719</otrq_prov_id> <clnt_dbid>1245439719</clnt_dbid> <mydate>6/19/2009 15:28:39</mydate> <amount>33222112121.212000</amount> </px> <px class_id_reference="1" object_id="_2"> <otrq_prov_id>1245439719</otrq_prov_id> <clnt_dbid>1245439719</clnt_dbid> <mydate>6/19/2009 15:28:39</mydate> <amount>33222112121.212000</amount> </px> <px class_id_reference="1" object_id="_3"> <otrq_prov_id>1245439719</otrq_prov_id> <clnt_dbid>1245439719</clnt_dbid> <mydate>6/19/2009 15:28:39</mydate> <amount>33222112121.212000</amount> </px> <px class_id_reference="1" object_id="_4"> <otrq_prov_id>1245439719</otrq_prov_id> <clnt_dbid>1245439719</clnt_dbid> <mydate>6/19/2009 15:28:39</mydate> <amount>33222112121.212000</amount> </px> <px class_id_reference="1" object_id="_5"> <otrq_prov_id>1245439719</otrq_prov_id> <clnt_dbid>1245439719</clnt_dbid> <mydate>6/19/2009 15:28:39</mydate> <amount>33222112121.212000</amount> </px> <px class_id_reference="1" object_id="_6"> <otrq_prov_id>1245439719</otrq_prov_id> <clnt_dbid>1245439719</clnt_dbid> <mydate>6/19/2009 15:28:39</mydate> <amount>33222112121.212000</amount> </px> <px class_id_reference="1" object_id="_7"> <otrq_prov_id>1245439719</otrq_prov_id> <clnt_dbid>1245439719</clnt_dbid> <mydate>6/19/2009 15:28:39</mydate> <amount>33222112121.212000</amount> </px> <px class_id_reference="1" object_id="_8"> <otrq_prov_id>1245439719</otrq_prov_id> <clnt_dbid>1245439719</clnt_dbid> <mydate>6/19/2009 15:28:39</mydate> <amount>33222112121.212000</amount> </px> <px class_id_reference="1" object_id="_9"> <otrq_prov_id>1245439719</otrq_prov_id> <clnt_dbid>1245439719</clnt_dbid> <mydate>6/19/2009 15:28:39</mydate> <amount>33222112121.212000</amount> </px> </t> </boost_serialization> -- V S P toreason(a)fastmail.fm -- http://www.fastmail.fm - Send your email first class

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importing boost-python module in python on windows
by Seema Jaisinghani 19 Jun '09

19 Jun '09

Hi, I have created an extension boost python module for C++ class, successfully using Visual Studio 2009, and get a shared library(.dll) as output. However I am having trouble importing this module in my python code. I have explicitly tried importing the dll as resource in an Eclipse PyDev project, and also set in windows PATH environment variable, the location for this dll. With the PATH set, I also tried import from the python shell, but no success. Can someone describe what is the process to import boost_python_modules in python on windows. Thanks, Seema

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Re: [Boost-users] [ptr_container] ptr_map and MinGW: "a declaration of assert must be available", even with cassert included
by philipp_muenzel＠web.de 19 Jun '09

19 Jun '09

Hi folks, Sorry for the confusion i've caused. It was a problem in my projects include-path, not with the include-path of gcc itself. I included files from another library i use, and this library contains a file named "assert.h" - why it was named so that it clashes with the system-assert i don't know. I renamed this file and altered it's #define include-guards. Now everything works. Thanks for reading my previous posts, I'm sorry for causing confusion with a problem that isn't boost-related at all. Regards, Philipp ___________________________________________________________________ WEB.DE FreeDSL Komplettanschluss mit DSL 6.000 Flatrate und Telefonanschluss für 17,95 Euro/mtl.! http://produkte.web.de/go/02/

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