August 2007 - Boost-users - lists.preview.boost.org

mpl question: object hierarchies
by Gross, Steve 13 Aug '07

13 Aug '07

Is there a way to use the mpl to determine if an object can be converted to some parent / child class? That is, if A derives from B, can I say something like "mpl::is_convertible_to<A, B>::value" ? Thanks, --Steve

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[ScopeExit/Typeof] Can't build simple test in debug mode (MSVC 7.1 and 8.0)
by Christian Larsen 13 Aug '07

13 Aug '07

Hi, I'm trying build a very simple test program using ScopeExit (just downloaded from the link in the review notice: http://boost-consulting.com/vault/index.php?action=downloadfile&filename=sco pe_exit-0.04.tar.gz&directory=& ). I'm using a brand new download of Boost 1.34.1 with it. The following code builds and runs fine in release mode in both VC7.1 and 8.0, but fails to build in debug mode in both versions. I also tried specifying the BOOST_TYPEOF_COMPLIANT in MSVC7.1 debug but to no avail - I just get some other errors. I couldn't find any indication of what would cause this difference between debug/release builds. I tried disabling optimizations in release mode to check whether this would cause release mode to fail, too, but it didn't. Any help would be appreciated. Best regards, Christian Larsen Code: #include <iostream> #include <boost/scope_exit.hpp> int main(int argc, char* argv[]) { bool commit = false; BOOST_SCOPE_EXIT( (commit) ) { if( !commit ) std::cerr << "Not committed!\n"; } BOOST_SCOPE_EXIT_END //commit = true; return 0; } Building debug mode MSVC 7.1: Compiling... ScopeExitTest.cpp using native typeof d:\Development\Misc\ScopeExitTest\ScopeExitTest.cpp(8) : error C2513: 'boost::type_of::msvc_typeid_wrapper<ID>::type' : no variable declared before '=' with [ ID=5 ] d:\Development\Misc\ScopeExitTest\ScopeExitTest.cpp(8) : error C2039: 'type' : is not a member of 'operator``global namespace''' d:\Development\Misc\ScopeExitTest\ScopeExitTest.cpp(8) : error C2440: 'type cast' : cannot convert from 'long' to 'boost::type_of::msvc_typeid_wrapper<ID>::type' with [ ID=5 ] No constructor could take the source type, or constructor overload resolution was ambiguous d:\Development\Misc\ScopeExitTest\ScopeExitTest.cpp(8) : error C2146: syntax error : missing ';' before identifier 'type' d:\Development\Misc\ScopeExitTest\ScopeExitTest.cpp(8) : error C2065: 'type' : undeclared identifier d:\Development\Misc\ScopeExitTest\ScopeExitTest.cpp(8) : error C2146: syntax error : missing ';' before identifier 'commit_boost_scope_exit_typeof' [...] Building debug mode MSVC 7.1 (with BOOST_TYPEOF_COMPLIANT): Compiling... ScopeExitTest.cpp using typeof emulation d:\Development\Misc\ScopeExitTest\ScopeExitTest.cpp(8) : error C2440: 'type cast' : cannot convert from 'long' to 'main::commit_boost_scope_exit_nested_typeof' Source or target has incomplete type d:\Development\Misc\ScopeExitTest\ScopeExitTest.cpp(8) : error C2143: syntax error : missing ';' before ':' d:\Development\Misc\ScopeExitTest\ScopeExitTest.cpp(8) : error C2143: syntax error : missing ';' before ':' d:\Development\Misc\ScopeExitTest\ScopeExitTest.cpp(8) : error C2143: syntax error : missing ';' before '{' d:\Development\Misc\ScopeExitTest\ScopeExitTest.cpp(8) : error C2039: 'type' : is not a member of 'operator``global namespace''' d:\Development\Misc\ScopeExitTest\ScopeExitTest.cpp(8) : error C2513: 'int' : no variable declared before '=' d:\Development\Misc\ScopeExitTest\ScopeExitTest.cpp(8) : error C2146: syntax error : missing ';' before identifier 'type' d:\Development\Misc\ScopeExitTest\ScopeExitTest.cpp(8) : error C2065: 'type' : undeclared identifier d:\Development\Misc\ScopeExitTest\ScopeExitTest.cpp(8) : error C2146: syntax error : missing ';' before identifier 'commit_boost_scope_exit_typeof' [...] Building debug mode MSVC 8.0: Compiling... ScopeExitTest.cpp using typeof emulation d:\development\misc\scopeexittest\scopeexittest.cpp(8) : error C2440: '<function-style-cast>' : cannot convert from 'long' to 'main::commit_boost_scope_exit_nested_typeof' Source or target has incomplete type d:\development\misc\scopeexittest\scopeexittest.cpp(8) : error C2143: syntax error : missing ';' before ':' d:\development\misc\scopeexittest\scopeexittest.cpp(8) : error C2143: syntax error : missing ';' before ':' d:\development\misc\scopeexittest\scopeexittest.cpp(8) : error C2143: syntax error : missing ';' before '{' d:\development\misc\scopeexittest\scopeexittest.cpp(8) : error C2039: 'type' : is not a member of '`global namespace'' d:\development\misc\scopeexittest\scopeexittest.cpp(8) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int d:\development\misc\scopeexittest\scopeexittest.cpp(8) : error C2513: 'int' : no variable declared before '=' d:\development\misc\scopeexittest\scopeexittest.cpp(8) : error C2146: syntax error : missing ';' before identifier 'type' [...]

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Boost Serialization with a dynamically loaded shared library
by Jeshua Bratman 13 Aug '07

13 Aug '07

I've been trying to get Boost serialization working for dynamically loaded shared libraries. Here's my basic structure simplified: 1. base.hpp - includes an abstract base class called base 2. derived.hpp - includes a derived class from base. includes base.hpp. 3. derived.cpp - includes code for derived class and for dynamically loading it 4. main.cpp - includes base.hpp but NOT derived.hpp. dynamically loads instantiates a base * which points to a derived object from derived.so Now in main I want to be able to serialize my pointer to the loaded derived class: base *obj = create_func(); //obj now points to a derived object obj->test(); //when test is run it correctly outputs the message from derived.cpp const base *to_serialize = obj; //it seems to want a const pointer in order to serialize std::ofstream ofs("filename"); boost::archive::text_oarchive oa(ofs); oa << (*to_serialize); main.cpp compiles fine, but when it gets to the last line there, the serialize method in base is called, not the one in derived. I read http://www.boost.org/libs/serialization/doc/serialization.html#derivedpoint… http://www.boost.org/libs/serialization/doc/serialization.html#derivedpoint… but it doesn't seem to address this problem (unless I missed something?). I can't use the BOOST_CLASS_EXPORT_GUID(derived, "derived") macro discussed on that page because main does not know what a derived object is (this is the whole point of having this plugin system). Is there any way I can make boost serialization correctly serialize the derived class from the base pointer when the derived object is known only to a dynamically loaded library? Thank you for your help, Jeshua Bratman -- View this message in context: http://www.nabble.com/Boost-Serialization-with-a-dynamically-loaded-shared-… Sent from the Boost - Users mailing list archive at Nabble.com.

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Re: [Boost-users] Regular expression min match length
by Raffaele Romito 13 Aug '07

13 Aug '07

Thanks for the reply John, I'll try to expose my "use case" with the hope this feature will be available in the future... I'm developing a system that detects TCP streams with a pattern matching, here is the pseudo code (in a simplified form) of the function I'd link to extend: protocol_stream decodeStream(tcp_stream) { foreach(registered protocol in the system) { required_size_to_match = calc_min_regex_len(current_protocol.regex); if(tcp_stream.buffer_size <= required_size_to_match) check if tcp_stream.buffer matches else try to read from tcp_stream if data is available until <required_size_to_match> and check again if matches } } Hope u can help since you have "an almost pathological interest in anything that can't be done" :) Thanks again _________________________________________________________________ C'è una nuova amica su Messenger… E' Doretta, vieni a conoscerla! http://www.doretta82.it/banner/index.html

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ScopeExit Review Begins Today
by Jody Hagins 13 Aug '07

13 Aug '07

The review period for Scope Exit Time Series, submitted by Alexander Nasonov, runs from Monday, August 13 until Wednesday, August 22. >From the documentation: Nowadays, every C++ developer is familiar with RAII technique. It binds resource acquisition and release to initialization and destruction of a variable that holds the resource. But there are times when writing a special class for such variable is not worth the effort. This is when ScopeExit macro comes into play. You put resource acquisition directly in your code and next to it you write a code that releases the resource. Note that ScopeExit uses PP macros and relies on Boost.Typeof. The latest version can is here: http://boost-consulting.com/vault/index.php?action=downloadfile&filename=sc… It's available also at http://tinyurl.com/2z6qg2 Online documentation is here: http://194.6.223.221/~nasonov/scope_exit-0.04/libs/scope_exit/doc/html/inde… >From the review guidelines here: http://boost.org/more/formal_review_process.htm ... Boost mailing list members are encouraged to submit Formal Review comments: * Publicly on the mailing list. * Privately to the Review Manager. Private comments to a library submitter may be helpful to her or him, but won't help the Review Manager reach a decision, so the other forms are preferred. What to include in Review Comments Your comments may be brief or lengthy, but basically the Review Manager needs your evaluation of the library. If you identify problems along the way, please note if they are minor, serious, or showstoppers. Here are some questions you might want to answer in your review: * 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. Thanks in advance to every for your participation in this review.

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[Lambda] Question about calling a member function inside a lambda construct
by Hendrik Belitz 13 Aug '07

13 Aug '07

Hello, I'm rather stucked in using lambda expressions for a presumably simple task. Suppose I have objects with a member function bool is_empty() const; stored in a vector: I want to count the number of objects for which their member functions returns false, which is simple, but not elegant to achieve by size_t sum = 0; for( Foo::const_iterator it = vec.begin(); it != vec.end(); ++it ) if ( it->is_empty() == false ) sum++; I want to exchange this for a lambda expression, and came up with the following after some thinking. for_each( begin(), end(), if_then( !(_1 ->* &GridCell::is_empty)(), var(sum)++ ) ); This is still wrong and leads to two error messages: error C2784: 'const boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lamb da::logical_action<Action>,boost::tuples::tuple<boost::lambda::lambda_functo r<T>>>> boost::lambda::operator !(const boost::lambda::lambda_functor<T> &)' : could not deduce template argument for 'const boost::lambda::lambda_functor<T> &' from 'boost::tuples::null_type' error C2675: unary '!' : 'boost::tuples::null_type' does not define this operator or a conversion to a type acceptable to the predefined operator Could anyone tell how to get this working? Regards Hendrik -- Hendrik Belitz ISD Software und Systeme GmbH Hauert 4 D - 44227 Dortmund Germany Fon: +49 (0)231/97 93-0 Fax: +49 (0)231/97 93-101 Mail: <mailto:hBelitz@isdcad.de> hBelitz(a)isdcad.de Internet: <http://www.isdcad.de/> www.isdcad.de Geschäftsführung: Günter Flassig (Vors.), Dr. Jörg Ruhwedel Sitz Dortmund, Amtsgericht Dortmund HRB 4601

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Fwd: Resizing a symmetric matrix
by Tinne De Laet 13 Aug '07

13 Aug '07

Hi, While using the most recent version of Boost (boost_1_34_1) I noticed some problems when resizing a symmetric matrix. I included a test program to illustrate the problems. (Recent SVN snapshots and boost 1.33 have the same problem) When executing I get the following error caused by resizing the symmetric matrix with the preserve option set to true: Resize ml to bigger size Check failed in file /home/fiep/sources/boost_1_34_1/boost/numeric/ublas/storage.hpp at line 196: i < size_ terminate called after throwing an instance of 'boost::numeric::ublas::bad_index' what(): bad index Aborted (core dumped) Note that are no problems when resizing normal matrices nor resizing symmetric matrices when the preserve option is set to false. When stepping into the program, it seems that something goes wrong with the indexing of the symmetric matrix. I suspect that problems are caused by the use of the matrix_resize_preserver routine which is called in case the preserve option is set to true. I think this routine is designed for normal matrices only and expects a matrix which is completely filled as opposed to a symmetric matrix in which only one triangle is filled. Do I use the library in a wrong way or might this be a BUG? Kind regards, Tinne De Laet _______________________________________ Tinne De Laet Department of Mechanical Engineering - PMA Katholieke Universiteit Leuven Celestijnenlaan 300B - bus 2420 3001 Heverlee Tel: +32 (0)16 32 25 33 http://people.mech.kuleuven.be/~tdelaet/ _______________________________________ Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm

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(no subject)
by Trigve Siver 13 Aug '07

13 Aug '07

Hi all, On gtkmm mailing was posted mail about using boost in gtkmm... Could someone post some info about API, ABI stability of boost? thanks Trigve mail from gtkmm list: //---------------------- Boost is not a stable API. If it ever declares API and ABI stability then we could use it. Using boost now would break already-installed applications and break compilation of applications when boost is upgraded. When parts of the Boost API become part of the official C++ standard then we would use that API where appropriate. For instance, we hope to port to a standard C++ signals API in the future. That API was largely based on libsigc++ anyway. On Mon, 2007-08-13 at 12:27 +0800, manphiz wrote: > Hi gtkmm developers: > > I'm a new-comer to gtkmm, who found gtkmm a ideal GUI toolkit based on > the philosophy of standard C++, which exactly matches my anticipation. > > On the other hand, glibmm/gtkmm is virtually a wrapper of gtk+ stuff, > which also has to reflect the interface of the original stuff. While > Boost is a well-known C++ library collection which has many overlaps in > many aspects with glibmm, such as smart pointer, thread support. > Recently, a feature request for weak pointer in glibmm and the recent > compose api proposed by Daniel Elstner are resemblances as > boost::weak_ptr and boost::format, which provide similar functionalities. > > Here's the question: whether to reuse Boost or to reinvent all needed > functionailities in glibmm? Though there seems a reluctance to use Boost > which already results in many reinvention in glibmm, I don't think it is > a good idea. Boost is becoming more and more widely used within C++ > community. To reinvent is simply a waste of resource, and may even > result in different design and implementation which will definitely > compromise the interoperability between Boost and gtkmm. With the fact > of gtk+ binding, I believe the existence of libsigc++ indicates > glibmm/gtkmm is not a zealot to become a strict binding with gtk+ stuff. > While Boost is indeed a much heavier library than libsigc++, it still > merits reusing in gtkmm. Moreover, many Boost stuff are going to become > part of C++0x, which means smart_ptr, threads, regex, etc. will become a > part of the language itself, which in turn will loose the need of some > stuff currently in glibmm. Due to the binding reality, it is impossible > to do everything in Boost, but some of them can benefit a lot. > > I wonder if such a migration to Boost is possible? A reimplementation > with gtkmm may be infeasible since it will destroy the binary > compatibility. Changing glibmm stuff to be a binding of Boost without > changing its interfaces sounds viable, which will ultimately save gtkmm > a lot of work in the long run. What do you think? > > _______________________________________________ > gtkmm-list mailing list > gtkmm-list(a)gnome.org > http://mail.gnome.org/mailman/listinfo/gtkmm-list -- murrayc(a)murrayc.com www.murrayc.com www.openismus.com _______________________________________________ gtkmm-list mailing list gtkmm-list(a)gnome.org http://mail.gnome.org/mailman/listinfo/gtkmm-list //---------------------- ____________________________________________________________________________________ Boardwalk for $500? In 2007? Ha! Play Monopoly Here and Now (it's updated for today's economy) at Yahoo! Games. http://get.games.yahoo.com/proddesc?gamekey=monopolyherenow

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Re: [Boost-users] boost::iostreams::gzip_compressor and multiplefiles
by John Reynolds 13 Aug '07

13 Aug '07

Yu can try zipios http://sourceforge.net/projects/zipios John Reynolds Aircraft Management Technologies Limited Registered in Ireland, No.337561 Registered office: 1 The Green, Malahide, Co.Dublin, Ireland Tel: + 353 1 8061000 Fax:+ 353 1 8061025 -----Original Message----- From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Jens Seidel Sent: 10 August 2007 13:22 To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] boost::iostreams::gzip_compressor and multiplefiles On Thu, Aug 09, 2007 at 11:38:58AM -0400, François Duranleau wrote: > On Thu, 9 Aug 2007, Robert Caldecott wrote: > >However, I want to create a single gzip file that contains multiple > >compressed > >files, each with a different filename. Does anyone know how to achieve > >this? > > I guess that when you uncompress the file (e.g. with gunzip), you want to > get all those named files in, well, different files? As far as I know, the > gzip format doesn't allow that (I could be wrong), hence the gzip'ed tar Right, it doesn't allow it and this is fine. Why should gzip allow archiving multiple files? It is a compressing program, not more. It's again the usual (and fine) Unix philosophy: one program for a simple task, combine/pipe multiple such simple programs to get more complex tasks done. This way you can also compress via gzip other archive formats, do not increase the code base of gzip and make compressing alone usable for other programs as well (which do not require tar). I would wish such a solution would be used on the proprietary systems which use ZIP as default archiver as well ... Jens _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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Problem message Boost Code Blocks
by question boost 13 Aug '07

13 Aug '07

Hi, using Code Blocks i got the folowing message: ld.exe "Cannot find -lboost_filesystem-mgw-mt-s-l_33_l". So I did :cd /jam source location/ then I execute build.bat Then, i put the following variables: path=C:\Program Files\CodeBlocks\bin BOOST_BUILD_PATH=C:\Documents and Settings\Administrateur\Bureau\boost_1_33_1\boost_1_33_1\tools\build\v2 BOOST_ROOT=C:\Documents and Settings\src\boost But i get the message again. What is the right thing to do in order not to get the message any more? Thank you for your answer because nobody has ever answered this question yet. Thank You _________________________________________________________________ Le blog Messenger de Michel, candidat de la Nouvelle Star : analyse, news, coulisses… A découvrir ! http://michel-nouvelle-star2007.spaces.live.com/

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