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[1.47.0] Beta 1 Release Notice
by Beman Dawes 25 Jun '11

25 Jun '11

Boost release 1.47.0 beta 1 is now available from SourceForge See http://sourceforge.net/projects/boost/files/ New Libraries: Chrono, Geometry, Phoenix and Ratio. Updated Libraries: Accumulators, Asio, Config, DateTime, Dynamic Bitset, Foreach, Function, Function Types, Graph, Iterator, Lexical Cast, Logic, Math, Meta State Machine, MultiIndex, Proto, Spirit, Tokenizer, Utility, Wave For details of what's in the release, see http://beta.boost.org/users/news/version_1_47_0. Note that the links to files on this web page are for the final release - use the SourceForge link above to get the beta files. There have been reports of build issues with MinGW/CGG and 64-bit Windows/VC++. These are being investigated and hopefully should be cleared up before the final release Please download the beta, give it a try, and report any problems you encounter. Thanks, -- The Boost Release Team Beman Dawes Daniel James Eric Niebler Rene Rivera Vladimir Prus

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Re: [Boost-users] Assign V2 - first impression
by er 24 Jun '11

24 Jun '11

Copied from devel: On 6/24/11 1:30 PM, er wrote: > On 6/24/11 9:08 AM, Stewart, Robert wrote: >> er wrote: >>> >>>> I am sure that it is a powerful library, but I really have no >>>> idea at all what is going on. I can't even parse the first >>>> line as valid C++ in any way. You need better examples, and >>>> also is that really the best way you could find to express >>>> repeating? >>> >>> If I try to imagine what the interface would look like after >>> taking into account some of the suggestions that were made, this >>> sentence: >>> >>> "Create data elements by mapping 1, 10, 100, 1000 by function >>> f, and insert each result in cont by invoking modifier >>> push_front." >> >> If I interpret that correctly, it would be clearer as: >> >> "Create elements in cont, using push_front(), by calling f() 1, 10, >> 100, and 1000 times." >> > > Apologies, I misread this. It should be : > > Map 1, 10, 100, and 1000 by function f, > which yields f( 1 ), f( 10 ), f( 100 ), f( 1000 ) > and insert each, n times, using push_front, in cont. > > T x; > > x = f( 1 ); > for(int i = 0; i < n; i++){ > cont.push_front( x ); > } > > x = f( 10 ); > for(int i = 0; i < n; i++){ > cont.push_front( x ); > } > > etc. > > The meaning of what is said next, I think, is not altered. >

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[Review] The 'Type Traits Introspection' library Review starst next friday, july 1st
by Joel falcou 24 Jun '11

24 Jun '11

According to the schedule, review for the Type Traits Introspection library by Edward Diener will run from friday, July 1st to monday, july 10 2011. =========== What is it? =========== The TTI library, which is an abbreviation for the 'Type Traits Introspection' library, allows a programmer to introspect at compile time the inner elements of a C++ type. The introspection process depends on specifying the name of the inner element by different macros for different types of elements, and then using a generated metafunction to determine whether that element exists within the enclosing type. The inner elements which can be introspected are type, class template, member data, member function, static member data, and static member function. The TTI library is based on the type_traits_ext portion of the Concept Traits Library, with improvements and additions, and also reproduces functionality ( without changing existing code ), for the purposes of completeness, from Boost.MPL regarding introspection of types and templates. The purpose of the library is to provide a consistent set of interfaces for doing compile-time introspection of a type, which other template metaprogrammers can use in their code. If you are at all interested in compile-time introspection of types, please take a look at the functionality of this library. =================== Getting the library =================== The library is available at http://svn.boost.org/svn/boost/sandbox/tti/ Note that this repository will be updated up to next thursday by Edward. =================== Writing a Review =================== The reviews and all comments should be submitted to the developers list, and the email should have "[TTI] Review" at the beginning of the subject line to make sure it's not missed. Please explicitly state in your review whether the library should be accepted. The general review checklist: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? And finally, every review should answer this question: - Do you think the library should be accepted as a Boost library? Be sure to say this explicitly so that your other comments don't obscure your overall opinion.

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[Regex] Emulate awk
by Alessandro Candini 24 Jun '11

24 Jun '11

I have a string like the following: string myStr = "Monthly Ecosystem NPP = 0.360591 tDM/ha month"; How can I use boost regex to isolate 0.360591, as I would do in bash with a echo $myStr | awk '{ print $5 }' ? Thanks in advance. -- Alessandro Candini MEEO S.r.l. Via Saragat 9 I-44122 Ferrara, Italy Tel: +39 0532 1861501 Fax: +39 0532 1861637 http://www.meeo.it ======================================== "ATTENZIONE:le informazioni contenute in questo messaggio sono da considerarsi confidenziali ed il loro utilizzo è riservato unicamente al destinatario sopra indicato. Chi dovesse ricevere questo messaggio per errore è tenuto ad informare il mittente ed a rimuoverlo definitivamente da ogni supporto elettronico o cartaceo." "WARNING:This message contains confidential and/or proprietary information which may be subject to privilege or immunity and which is intended for use of its addressee only. Should you receive this message in error, you are kindly requested to inform the sender and to definitively remove it from any paper or electronic format."

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Re: [Boost-users] [review][assign] Formal review of Assign v2 ongoing
by er 24 Jun '11

24 Jun '11

Copy from devel: > I am sure that it is a powerful library, but I really have no idea at all what is going on. I can't even parse the first line as valid C++ in any way. You need better examples, and also is that really the best way you could find to express repeating? If I try to imagine what the interface would look like after taking into account some of the suggestions that were made, this sentence: "Create data elements by mapping 1, 10, 100, 1000 by function f, and insert each result in cont by invoking modifier push_front." translates to ( push_front<1>( cont ) % ( _data = f ) % ( _repeat = n ) )( 1, 10, 100, 1000 ); Questions : - is it more readable, now? - What if each example was preceded by its English equivalent. Is this a bit of stretch or a reasonable approach? Thanks.

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[Asio] Crash on service delete
by Indrek Sünter 24 Jun '11

24 Jun '11

Hi. I'm experiencing a crash when io_service destructor is called. The service was run on a separate thread and a socket was associated with it. The destruction sequence (on main thread, where the service was constructed) was as follows: // m_socket was associated with m_service m_socket->cancel(); m_socket->shutdown( boost::asio::ip::tcp::socket::shutdown_both, ec ); m_socket->close( ec ); delete m_socket; m_socket = NULL; // Delete work on the service delete m_work; m_work = NULL; // Stop the service m_service->stop(); // Join the thread this service was running on m_thread->interrupt(); m_thread->join(); delete m_thread; m_thread = NULL; // Crashes here delete m_service; m_service = NULL; Here's what VC10 reported: Access violation camc.exe!boost::asio::detail::socket_ops::send(unsigned int s, const _WSABUF * bufs, unsigned int count, int flags, boost::system::error_code & ec) Line 876 + 0x24 bytes C++ camc.exe!boost::asio::detail::socket_select_interrupter::interrupt() Line 127 + 0x18 bytes C++ camc.exe!boost::asio::detail::select_reactor::shutdown_service() Line 73 C++ camc.exe!boost::asio::detail::service_registry::~service_registry() Line 42 + 0xf bytes C++ camc.exe!boost::asio::detail::service_registry::`scalar deleting destructor'() + 0x16 bytes C++ camc.exe!boost::asio::io_service::~io_service() Line 51 + 0x1f bytes C++ camc.exe!boost::asio::io_service::`scalar deleting destructor'() + 0x16 bytes C++ Code crashes on Windows 7 (64bit, boost 1.46.1) and works on Ubuntu 11.04 (64bit, boost 1.42.0). Any ideas on what I'm missing? Thanks

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Directory Iterator / Directory "access denied" exception
by Kiah08 24 Jun '11

24 Jun '11

Does anyone know of a way to handle exceptions when a directory is inaccessible? I would like to be able to resume the directory scan after the inaccessible directory. Please give an in depth example if possible. Using Boost 1.46. -- View this message in context: http://boost.2283326.n4.nabble.com/Directory-Iterator-Directory-access-deni… Sent from the Boost - Users mailing list archive at Nabble.com.

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Graph Isomorphism
by Evan Driscoll 24 Jun '11

24 Jun '11

I am writing a library for a variant of finite automata. States in the automata are named by "keys", which boil down to unsigned ints. For testing purposes, I'd like to be able to test whether two automata are isomorphic -- i.e. they are the same except for perhaps different keys for the corresponding states. (The motivation for this is that there are a few operations like 'determinize' that I don't want to guarantee any particular names for the output states, but I want or need to test something stronger than language equality between the actual and respected result.) One way I've thought of doing this is to convert the transition graph of each automaton to a BGL graph and use it's 'isomorphism' function to determine whether the two are isomorphic. However, I'd need to impose two extra conditions: - Edges between nodes are labeled (with the symbol that makes the automaton take that transition), and I need to make sure these match between the two graphs - Nodes are labeled (with whether they correspond to an initial and accepting state of the automaton), and I need to make sure these match up between the two graphs Does it sound like this task is something the BGL is suited for? Thanks, Evan Driscoll

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compile error with boost trunk and clang trunk
by Dane Springmeyer 23 Jun '11

23 Jun '11

Anyone else running latest clang and boost and running into compile errors? I'm hitting a problem with __is_pod in type traits. More details here: https://svn.boost.org/trac/boost/ticket/5635 Let me know if there is anything else I can test to make sure its not something special about my setup. Dane

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[boost 1.42, gcc 4.4, ubuntu 10.10] Program hangs when using barrier.wait() even though all threads have reached wait.
by Gareth 23 Jun '11

23 Jun '11

I'm having problems with boost::barrier. I've written a class that creates a thread pool to map evaluate an array of functions to an array of results. I've used barriers in the synchronisation. The problem is that the threads are all getting stuck at the barrier::wait calls. I've verified with gdb that all the worker threads and the manager thread are sitting in barrier::wait() however, there all stuck. I have no idea what's causing this. I've put the source code in the following github gist and also pasted it to the end of the email. https://gist.github.com/1041351 I've also checked the bugs list for any known bugs, fixed or otherwise, to do with threading and I haven't found anything. I'm not sure what I'm doing wrong. -Gareth Charnock /* compile: g++ thread_template.cpp -lboost_thread Outputs: BOOST_VERSION = 104200 Starting thread 0 Starting thread 1 Thread 0 waiting for work Thread 1 waiting for work Threads have work... */ #include <boost/version.hpp> #include <boost/thread.hpp> #include <boost/thread/barrier.hpp> #include <boost/function.hpp> #include <iostream> #include <vector> template<typename T> class Multithreader { public: Multithreader() : numCPU(sysconf(_SC_NPROCESSORS_ONLN)), _barrier(numCPU+1), mFuncs(NULL), mMapTo(NULL) { std::cout << "BOOST_VERSION = " << BOOST_VERSION << std::endl; //Start the thread pool for(long i = 0;i<numCPU;i++) { std::cout << "Starting thread "<<i<< std::endl; boost::thread(WorkerThread(i,this)); } } ~Multithreader() { //Terminate the threads //todo } void map(const std::vector<boost::function<T ()> >& funcs,std::vector<T>& mapTo) { mFuncs = &funcs; mMapTo = &mapTo; std::cout << "Threads have work..." << std::endl; _barrier.wait(); //Workers are working at this point std::cout << "Threads are working..." << std::endl; _barrier.wait(); std::cout << "Threads have finished" << std::endl; } private: const std::vector<boost::function<T ()> >* mFuncs; std::vector<T>* mMapTo; boost::barrier _barrier; size_t numCPU; class WorkerThread { public: WorkerThread(long _id,Multithreader* _parent) : id(_id),parent(_parent) { } void operator()() { while(true) { std::cout << "Thread "<<id<<" waiting for work" << std::endl; parent->_barrier.wait(); std::cout << "Thread "<<id<<" has work" << std::endl; //Do work for(long i = id;i<parent->mFuncs->size();i+=parent->numCPU) { parent->mMapTo->at(i) = parent->mFuncs->at(i)(); } parent->_barrier.wait(); std::cout << "Thread "<<id<<" finished the work" << std::endl; } } long id; Multithreader* parent; }; }; #include <boost/bind.hpp> double f(double x) { return x*2; } int main() { //Start the thread pool Multithreader<double> mt; std::vector<boost::function<double()> > work;work.resize(20); std::vector<double> results;results.resize(20); //Prepare the work for(unsigned long i = 0;i<20;i++) { work[i] = boost::bind(f,i); } //Execute in parallel mt.map(work,results); while(true) { //For the purposes of the example, keep the main thread alive //so we don't delete mt } }

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