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[Serialization] How do I serialize derived classes via a template class of type base class?
by Neil Monday 07 Jul '10

07 Jul '10

I am having a problem where I am trying to serialize a message of a template class. The template's class message is of type BaseClass, but I want it to serialize the derived versions of the class. As of right now, it is only serializing the BaseClass. How am I supposed to register with boost::serialization the types of the derived classes that I want it to serialize? I have tried several methods such as using the 'BOOST_CLASS_EXPORT' macro. I have also tried boost::serialization::void_cast_register(). Also, I have tried using this example: ar.register_type(static_cast<bus_stop_corner *>(NULL)); from here: http://www.boost.org/doc/libs/1_36_0/libs/serialization/example/demo_gps.hpp but still no luck. It seems to me that all of the things I have posted above are different ways to achieve the same end result: serialize a derived class via a base class pointer. But I am not clear on when to use which one, and which method is appropriate for my case. Here is an example of what my code is like: template <class T> class Frame{ ... private: T message; }; class BaseType{}; class SubTypeA : public BaseType{}; class SubTypeB : public BaseType{}; int main(){ std::vector< Frame<BaseType> > myFrames; //add a bunch of Frame<SubTypeA> and Frame<SubTypeB> objects to the myFrames vector. //serialize the vector. return 0; } This code is not compilable at all, but was included to give you an idea of the structure of my program. I am pretty new to mailing lists, so I apologize if I am not using proper formatting etc.

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Boost MPI, error to get message
by Jack Bryan 07 Jul '10

07 Jul '10

Dear All : I designed a master-worker framework with boost MPI, in which the master can schedulemultiple tasks (numTaskPerWorkerNode) to each worker and then collects results from workers. if the numTaskPerWorkerNode = 1, it works well. But, if numTaskPerWorkerNode > 1, the master cannot get the results from workers. But, the workers can get the tasks from master. why ? I have used different taskTag to distinguish the tasks, but still does not work. Any help is appreciated. Thanks, Jack July 4 2010 _________________________________________________________________ Hotmail has tools for the New Busy. Search, chat and e-mail from your inbox. http://www.windowslive.com/campaign/thenewbusy?ocid=PID28326::T:WLMTAGL:ON:…

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boost MPI error MPI_ERR_TRUNCATE: message truncated
by Jack Bryan 07 Jul '10

07 Jul '10

Dear All: I need to transfer some messages from workers master node on MPI cluster with Open MPI. I use boost MPI API in my program. The number of messages is fixed. When I increase the number of worker nodes, i got error: ------------------------------------------ terminate called after throwing an instance of 'boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::mpi::exception> >' what(): MPI_Unpack: MPI_ERR_TRUNCATE: message truncated[n231:45873] *** Process received signal ***[n231:45873] Signal: Aborted (6)[n231:45873] Signal code: (-6)[n231:45873] [ 0] /lib64/libpthread.so.0 [0x3c50e0e4c0][n231:45873] [ 1] /lib64/libc.so.6(gsignal+0x35) [0x3c50230215][n231:45873] [ 2] /lib64/libc.so.6(abort+0x110) [0x3c50231cc0] -------------------------------------------------------------- For 40 workers , it works well. But for 50 workers, it got this error. The largest message size is not more then 72 bytes. Any help is appreciated. thanks Jack July 7 2010 _________________________________________________________________ The New Busy is not the too busy. Combine all your e-mail accounts with Hotmail. http://www.windowslive.com/campaign/thenewbusy?tile=multiaccount&ocid=PID28…

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previously working boost code breaks with c++0x
by Nathan Ridge 07 Jul '10

07 Jul '10

Hello, The following code, which compiles just fine with g++ 4.4 without the --std=c++0x flag, gives an error with that flag: #include <string> #include <boost/tuple/tuple.hpp> #include <boost/algorithm/string.hpp> using boost::make_tuple; void f(int i, const std::string& s) { boost::tuple<int, std::string> t; t = make_tuple(i, s); } test.cpp: In function ‘void f(int, const std::string&)’: test.cpp:12: error: no match for ‘operator=’ in ‘t = std::make_tuple(_Elements&& ...) [with _Elements = int&, const std::basic_string<char, std::char_traits<char>, std::allocator<char> >&](((const std::basic_string<char, std::char_traits<char>, std::allocator<char> >&)((const std::string*)s)))’ Note that any one of the following makes the code compile: 1) Removing the --std=c++0x flag 2) Removing the <boost/algorithm/string.hpp> include 3) Removing the using boost::make_tuple declaration and explciitly qualifying boost::make_tuple in f(). What is going on? Thanks, Nate. _________________________________________________________________ Learn more ways to connect with your buddies now http://go.microsoft.com/?linkid=9734388

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Statistical Accumulator
by Kraus Philipp 07 Jul '10

07 Jul '10

Hi, I try to calulate the covariance from some data. http://www.boost.org/doc/libs/1_43_0/doc/html/accumulators/user_s_guide.htm… I don't understand the call "acc call". I would like to rebuild the cov command form Matlab for matrix data (http://www.mathworks.com/access/helpdesk/help/techdoc/ref/cov.html ). If this is correct, when I give as the first argument of command data from the first line and second as the data of the first column to the first value to calculate the new matrix? I try try compile the excample, but I get a compiler error on the "acc::tag::covariate1": acc::accumulator_set<double, acc::stats<acc::tag::covariance<double, acc::tag::covariate1> > > xx; xx(1., acc::tag::covariate1 = 2.); xx(1., acc::tag::covariate1 = 4.); xx(2., acc::tag::covariate1 = 3.); xx(6., acc::tag::covariate1 = 1.); std::cout << acc::covariance(xx) << std::endl; The error text: "expected primary-expression befor = token". Sorry, it's a little bit late, so I don't see my mistake Thanks Phil

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[Bind] Placeholders passed by reference?
by Robert Jones 07 Jul '10

07 Jul '10

This works exactly as expected... void f( unsigned & val ) { val *= 2; } unsigned i = 3; boost::bind( f, _1)( i ); with i being doubled. What I don't get is why I don't need to say boost::bind( f, boost::ref( _1 ) )( i ); and conversely how I specify that I want bind to pass by value rather than by reference for the placeholder. Thanks - Rob.

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Thread ID
by Kraus Philipp 07 Jul '10

07 Jul '10

Hi, I need for initialisation the random values on a cluster (64 cores on 8 machines) different seeds. I would like to use the time and thread id: I can't use only the time, because I will get the same random numbers on every core, so I would like to use thread id and time together. I dont' work with boost threads, so I try to read the thread id with boost::thread::get_id(). Compiling works, but on linking I get the error "that boost threads can't linking", but I don't have any library like "boost thread" ? Should I compile the library like the iostream lib? Is this the right way to read the thread id? I need only a value which I can use for the random seed of all cores and the value must be different on every core. Thanks for help Phil

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asio, new connection handler is not called
by Lloyd 07 Jul '10

07 Jul '10

Hi, In our application, inside the "main()" a tcp port made to listen, and the io_service is ran. It receives connection, and reads data from the connection. Then it create a thread and passes the "io_service" and the related "socket" as a reference to the new thread. Further communication are performed inside the thread. So far this works fine. Now inside the thread, I have created a "thread interruption point". This thread interruption point is inside a while loop for testing, and the while loop is inside the "async_read_handler". (That is the read handler never returns - When testing code is execution control is here-). By opening a new "telnet client", I have tried to connect to the listening port, it is connected, but the async_accept handler routine is not called! What could be the reason? How can I rectify this? Thanks, Lloyd ______________________________________ Scanned and protected by Email scanner

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Serialization of boost::gregorian::date
by Nguyen Kim Son 07 Jul '10

07 Jul '10

Hello, Do you know how to serialize class boost::gregorian::date? More generally, is it possible to serialize a class in whose we can't change the code source ? Thanks in advance, Son. -- --------------------------------------------------------- Son NGUYEN KIM Antibes 06600 Tel: 06 48 28 37 47

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Whence Ranges?
by John Dlugosz 07 Jul '10

07 Jul '10

1) Given the existance of <http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1871.html>, should <http://en.wikipedia.org/wiki/C%2B%2B_Technical_Report_1#Technical_Report_2> include "Boost Range Library" on the list of things proposed for TR2? 2) Is it going well? That is, should I expect this to be standardized eventually, or have the library workers moved away from it somehow? 3) I've run into various other things like "rangeEx" and "oven" that are what? Extensions? Rewrites? What's out there that I ought to look into, for foundational use in new code? Thanks, --John (stupid footer below) TradeStation Group, Inc. is a publicly-traded holding company (NASDAQ GS: TRAD) of three operating subsidiaries, TradeStation Securities, Inc. (Member NYSE, FINRA, SIPC and NFA), TradeStation Technologies, Inc., a trading software and subscription company, and TradeStation Europe Limited, a United Kingdom, FSA-authorized introducing brokerage firm. None of these companies provides trading or investment advice, recommendations or endorsements of any kind. The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and delete the material from any computer.

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