July 2009 - Boost-users - lists.preview.boost.org

[boost-users][bind] type of boost::bind
by Sakharuk, Vlad (GMI Development) 24 Jul '09

24 Jul '09

Here is example: struct a{ int foo(bool){ return 0; } }; boost::function1<int, void> func = bind(&a::foo,_1,false); a somea; func(somea); Is it possible to get a bind type? Something like: boost::mpl::identity<boost::bind<int,void,boost::arg<1>,a> >::type abind; Thanks Vlad. -------------------------------------------------------------------------- This message w/attachments (message) may be privileged, confidential or proprietary, and if you are not an intended recipient, please notify the sender, do not use or share it and delete it. Unless specifically indicated, this message is not an offer to sell or a solicitation of any investment products or other financial product or service, an official confirmation of any transaction, or an official statement of Merrill Lynch. Subject to applicable law, Merrill Lynch may monitor, review and retain e-communications (EC) traveling through its networks/systems. The laws of the country of each sender/recipient may impact the handling of EC, and EC may be archived, supervised and produced in countries other than the country in which you are located. This message cannot be guaranteed to be secure or error-free. References to "Merrill Lynch" are references to any company in the Merrill Lynch & Co., Inc. group of companies, which are wholly-owned by Bank of America Corporation. Securities and Insurance Products: * Are Not FDIC Insured * Are Not Bank Guaranteed * May Lose Value * Are Not a Bank Deposit * Are Not a Condition to Any Banking Service or Activity * Are Not Insured by Any Federal Government Agency. Attachments that are part of this E-communication may have additional important disclosures and disclaimers, which you should read. This message is subject to terms available at the following link: http://www.ml.com/e-communications_terms/. By messaging with Merrill Lynch you consent to the foregoing. --------------------------------------------------------------------------

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[MPI] Serializing a class with a string data member
by Mathieu Larose 23 Jul '09

23 Jul '09

Hello, I'm trying to register a class (named A), because it will be a derived class. Calling BOOST_CLASS_EXPORT(A) will generate a lot of errors that look similar. Here is one of them: /usr/local/include/boost/mpi/datatype.hpp:184: error: no matching function for call to ‘assertion_failed(mpl_::failed************ boost::mpi::is_mpi_datatype<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >::************)’ Here is the code: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - #include <iostream> #include <boost/mpi.hpp> #include <boost/archive/text_iarchive.hpp> #include <boost/archive/text_oarchive.hpp> #include <boost/mpi/packed_oarchive.hpp> #include <boost/mpi/packed_iarchive.hpp> #include <boost/serialization/export.hpp> #include <boost/serialization/string.hpp> class A { friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & _text; } }; BOOST_CLASS_EXPORT(A); // I need to export A, because I will use // abstract base pointer. A is not a derived // class for simplicity here. int main(int argc, char * argv[]) { return 0; } - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - I've found that someone had the same problem ( http://groups.google.com/group/boost-list/msg/c9a0c133bddd783d ), but no solution was found. What am I doing wrong? Thanks, Mathieu Larose

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[BGL] Converting between adjacency_list with listS and vecS
by Ethan Kim 23 Jul '09

23 Jul '09

Hi all, The long standing question I've had for BGL is how to easily convert a graph (using adjacency_list) from listS as vertex list to vecS. (And vice versa) I understand why there needs to be 2 different implementations depending on different uses of algorithms. But is there an easy way to convert them back and forth? Any tip would be much appreciated. Thanks,

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[Thread] Interruption Feature
by Timothy 23 Jul '09

23 Jul '09

Hi, I want to write a signal handler for SIGINT that notifies the main() thread to break out of a loop and exit. I was thinking of using Boost.Thread's interruption feature. Does it support this usage, or do I need to use some other way to do this? Thanks in advance. Tim

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Other tcp stream examples? suggestion about asio examples... Re: usage of boost::asio::async_write and boost::asio::buffer
by Ozgur Ozturk 23 Jul '09

23 Jul '09

Hi All, Thanks to Igor's pointing to streambuf I realized availability of stream operations. I think for many newbies, stream examples would be easier to understand/reuse. I found the very simple daytime_client and daytime_server examples useful. (Examples could be reordered to start with simpler ones.) Are there any other asio examples using streams? If the contributors could add stream versions of chat server and client examples that would be great. I guess using streams is somewhat less efficient, is that correct? (since you have more control on the buffer without streams.) Best regards, Ozgur (Oscar) Ozturk www.DrOzturk.com Phone: +1 (908) DROZGUR i.e, +1 (908) 376-9487 On Tue, Jul 21, 2009 at 4:28 PM, Igor R <boost.lists(a)gmail.com> wrote: > > I tried to use the same string as buffer for both async_read_some and > async_write > > Who will allocate the buffer for the read operation? socket's > async_read_some() doesn't know to do this alone. > > > I guess the string can not be treated as a mutable buffer, so maybe I > should > > keep the original char * buffer for async_read_some and use the string > only > > for outputting with async_write. Is that right? > > (or any other recommendation?) > > Why wouldn't you use asio::streambuf? You've a set of functions that > async.read/write from/to it, and it grows automatically. You can see > relevant examples in asio docs. > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users >

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synchronous vs asynchronous...
by Ozgur Ozturk 23 Jul '09

23 Jul '09

Hi, I am kind of new to multithreaded programming and network programming, so I had some difficulty with the examples. Can you confirm an epiphany I had? - I was thinking I had to use the asynchronous functions to handle multiple clients, now I understand that you can achieve same things with synchoronous ones w/ threads and you can write equally efficient code?. (It is only a different pattern; some people find the code more manageable the async way, since they don't need to handle threads themselves.) Is this new understanding true? - If no (if there is some efficiency difference), is it significant? (Otherwise, for the initial prototype of our software, I may use still use synchronous sockets w/ threads, since I am still not very comfortable with async.) Best regards, Ozgur (Oscar) Ozturk www.DrOzturk.com Phone: +1 (908) DROZGUR i.e, +1 (908) 376-9487

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ASIO async_read_until...
by Etienne Philip Pretorius 23 Jul '09

23 Jul '09

Hello list, I have a set of inherited classes as follows: client [parent of] stream [parent of] parser [parent of] grammar When I perform the following call: boost::asio::async_read_until( socket_, streambuf_, stream::parse(), boost::bind( &client::handle_read, this, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred ) ); The xml::parser::operator() call for the match condition is a copy of the classes: parser [parent of] grammar I need to know if someone could suggest a client way for me to use (shared) pointers to the classes so that the xml::parser::operator() can keep its state changes over successive calls for async_read_until. Currently I have this (hack) for the issue, but hope there is a cleaner approach: class parser : public grammar { public: parser( ) : parser_(//stupid hack... this ) { }; virtual ~parser( ) { }; parser& parse( ) { return *this; }; template <typename T> std::pair<T, bool> operator()( T begin, T end ) { ...[state changes based on content matches]... }; private: parser* parser_;//needed for stupid hack... protected: }; When I call stream::parse() it returns the parser object, at which async_read_until makes a copy of the parser object and its base classes. When parser::operator() is called by async_read_until, I then apply all state changes via parser* parser_ to the original class. Any suggestions are welcome. Etienne.

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Statechart compile error on OS X
by Daniel Dilts 23 Jul '09

23 Jul '09

I'm trying to use Boost.Statechart in an iPhone development project. When I build the Hello World example in a .mm file (Objective C++) I get an error "error: no class template named 'rebind' in 'struct Machine'". If, in the same project, I build the statemachine in a .cpp file (C++) and call a C function from a .mm file it works perfectly. Is there a compiler flag or project setting that I need to change to get the state machine to work from a .mm file? I would really like the state machine to be a member of an Objective C class.

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Important: Subversion upgrade on Saturday, July 25
by Doug Gregor 23 Jul '09

23 Jul '09

We will be upgrading Boost's Subversion server and the Boost Subversion repository to Subversion 1.6.3. This upgrade will bring the new features provided by the Subversion 1.5.x and 1.6.x released to Boost, including merge tracking: http://subversion.tigris.org/svn_1.5_releasenotes.html http://subversion.tigris.org/svn_1.6_releasenotes.html The upgrade will begin on Saturday, July 25 at 8:00AM EST, and is likely to take all day. During this upgrade, the Boost Subversion repository, Trac, and mailing list archives will be inaccessible. However, the Boost mailing lists should still function normally. I will send a note to the Boost list when the upgrade is complete. Thank you for your patience. - Doug

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boost 1.39 serialization via base pointer ok on gcc, but crashes on AIX V10.1
by Avi Bahra 23 Jul '09

23 Jul '09

Take the following small self contained example. This compiles and runs without any problems on gcc 4.2.1 on SUSE Linux. However on AIX v10.1 compiler, you see the following on compile: "/s1a/emos_esuite/emos_data/sms/boost_1_39_0/boost/archive/detail/oserializer.hpp", line 538.5: 1540-2400 (W) "boost::serialization::STATIC_WARNING" is undefined. The delete operator will not call a destructor. "/s1a/emos_esuite/emos_data/sms/boost_1_39_0/boost/archive/detail/oserializer.hpp", line 530.13: 1540-0700 (I) The previous message was produced while processing "boost::archive::save<boost::archive::text_oarchive,Defs>(text_oarchive "/s1a/emos_esuite/emos_data/sms/boost_1_39_0/boost/archive/detail/common_oarchive.hpp", line 64.9: 1540-0700 (I) The previous message was produced while processing "boost::archive::detail::common_oarchive<boost::archive::text_oarchiv. "/s1a/emos_esuite/emos_data/sms/boost_1_39_0/boost/archive/basic_text_oarchive.hpp", line 75.13: 1540-0700 (I) The previous message was produced while processing "boost::archive::basic_text_oarchive<boost::archive::text_oarchive>::sa "/s1a/emos_esuite/emos_data/sms/boost_1_39_0/boost/archive/detail/interface_oarchive.hpp", line 64.21: 1540-0700 (I) The previous message was produced while processing "boost::archive::detail::interface_oarchive<boost::archive::text_. "src/TestSerialisation2.cpp", line 86.20: 1540-0700 (I) The previous message was produced while processing "main()". vacpp.compile.c++ bin/vacpp/debug/src/TestSerialisation.o When the program is run, the following is produced by the debugger: Can't read type info for "basic_pointer_oserializer": Expecting mangled name, and didn't find one. Can't read type info for "basic_pointer_iserializer": Expecting mangled name, and didn't find one. Can't read type info for "singleton<boost__archive__detail__<unnamed>__guid_initializer<RepeatDate> >": Expecting ":", and didn't find one. Can't read type info for "singleton_wrapper<boost__archive__detail__<unnamed>__guid_initializer<RepeatDate> >": Expecting ":", and didn't find one. Can't read type info for "error_info_container": Expecting mangled name, and didn't find one. Can't read type info for "init_guid<RepeatDate>": Expecting ":", and didn't find one. it then throw an exception: archive_exception::unregistered_cast This is because the it thinks that Base/Derived class relationship has not been registered. (i.e RepeatBase/RepeatDerived in the enclosed example). It appears that: ar & boost::serialization::base_object<RepeatBase>(*this); is not registering the base/derived relationship on AIX. The actual point in the code where is throws an exception is >>>>>>>>>: // convert pointer to more derived type. if this is thrown // it means that the base/derived relationship hasn't be registered vp = serialization::void_downcast( *true_type, *this_type, static_cast<const void *>(&t) ); if(NULL == vp){ boost::serialization::throw_exception( >>>>>> archive_exception(archive_exception::unregistered_cast) ); } In the debugger variables true_type and this_type are of type boost::serialization::extended_type_info true_type: m_type_info_key unsigned int const 0x1100121b8 0x00000001 (1) m_key $string const * 0x1100121c0 0x1000b9748 -> "RepeatDerived" this_type: m_type_info_key unsigned int const 0x110012a40 0x00000001 (1) m_key $string const * 0x110012a48 0x00000000 It looks like the m_key data member of this_type is empty, I expected "RepeatBase" Has any one else hit a similar problem, where on one platform its ok and another it crashes ? Are there any workarounds I could try ? -- Best regards, Ta, Avi

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