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

boost 1.34.1 cygwin build error.
by chun ping wang 27 Jul '07

27 Jul '07

I change user-config.jam to add "using python : : /usr/bin/python2.5 ;" $ ./bjam --toolset=gcc --prefix=/usr/boost-install install Building Boost.Regex with the optional Unicode/ICU support disabled. Please refer to the Boost.Regex documentation for more information (don't panic: this is a strictly optional feature). /usr/src/boost_1_34_1/tools/build/v2/tools/stage.jam:424: in object(installed-sh ared-lib-generator)(a)4.run *** argument error * rule virtual-target.register ( target ) * called with: ( object(file-target)@1396 object(file-target)@1397 ) * extra argument object(file-target)@1397 /usr/src/boost_1_34_1/tools/build/v2/build/virtual-target.jam:880:see definition of rule 'register' being called /usr/src/boost_1_34_1/tools/build/v2/build/generators.jam:840: in try-one-genera tor-really /usr/src/boost_1_34_1/tools/build/v2/build/generators.jam:902: in try-one-genera tor /usr/src/boost_1_34_1/tools/build/v2/build/generators.jam:1110: in construct-rea lly /usr/src/boost_1_34_1/tools/build/v2/build/generators.jam:1186: in generators.co nstruct /usr/src/boost_1_34_1/tools/build/v2/tools/stage.jam:160: in construct /usr/src/boost_1_34_1/tools/build/v2/build/targets.jam:1242: in object(install-t arget-class)(a)85.generate /usr/src/boost_1_34_1/tools/build/v2/build/targets.jam:765: in generate-really /usr/src/boost_1_34_1/tools/build/v2/build/targets.jam:738: in object(main-targe t)(a)246.generate /usr/src/boost_1_34_1/tools/build/v2/build/targets.jam:895: in targets.generate- from-reference /usr/src/boost_1_34_1/tools/build/v2/build/targets.jam:1169: in generate-depende ncies /usr/src/boost_1_34_1/tools/build/v2/build/targets.jam:1214: in object(alias-tar get-class)(a)89.generate /usr/src/boost_1_34_1/tools/build/v2/build/targets.jam:765: in generate-really /usr/src/boost_1_34_1/tools/build/v2/build/targets.jam:738: in object(main-targe t)(a)248.generate /usr/src/boost_1_34_1/tools/build/v2/build/targets.jam:895: in targets.generate- from-reference /usr/src/boost_1_34_1/tools/build/v2/build/targets.jam:1169: in generate-depende ncies /usr/src/boost_1_34_1/tools/build/v2/build/targets.jam:1214: in object(alias-tar get-class)(a)97.generate /usr/src/boost_1_34_1/tools/build/v2/build/targets.jam:765: in generate-really /usr/src/boost_1_34_1/tools/build/v2/build/targets.jam:738: in object(main-targe t)(a)252.generate /usr/src/boost_1_34_1/tools/build/v2/build-system.jam:402: in load /usr/src/boost_1_34_1/tools/build/v2/kernel/modules.jam:261: in import /usr/src/boost_1_34_1/tools/build/v2/kernel/bootstrap.jam:132: in boost-build /usr/src/boost_1_34_1/boost-build.jam:9: in module scope

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Creating an equivalent to java's System.currentTimeMillis
by Philippe Mondon 27 Jul '07

27 Jul '07

Hi, I'm trying to build an equivalent to java's System.currentTimeMillis() using boost framework, and I've done something like that : #include <boost/date_time/posix_time/posix_time.hpp> using namespace boost::gregorian; using namespace boost::posix_time; //.... Other code long Utils::getCurrentTime() { ptime now(microsec_clock::universal_time()); date d(1970,boost::date_time::Jan,01); ptime torigin(d); //midnight //time_duration tduration = now - torigin; time_period tperiod(torigin,now); //long returnVal = tduration.total_milliseconds(); long returnVal = tperiod.length().total_milliseconds(); cout << "Current time : " << returnVal << endl; return returnVal; } Unfortunately, it gives only a 8 digit number (in java you've got a 13 digit number when using currentTimeMillis) so I suspect that it does not give a duration since Jan the 1st 1970 (which is java reference). Do you have an idea of how to achieve the writing of this piece of code? Thanks, regards. Philippe Mondon Equipe PAC/Architecture DIMC Calyon Ce message et ses pièces jointes (le "message") est destiné à l'usage exclusif de son destinataire. Si vous recevez ce message par erreur, merci d'en aviser immédiatement l'expéditeur et de le détruire ensuite. Le présent message pouvant être altéré à notre insu, CALYON Crédit Agricole CIB ne peut pas être engagé par son contenu. Tous droits réservés. This message and/or any attachments (the "message") is intended for the sole use of its addressee. If you are not the addressee, please immediately notify the sender and then destroy the message. As this message and/or any attachments may have been altered without our knowledge, its content is not legally binding on CALYON Crédit Agricole CIB. All rights reserved.

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[interprocess] Problems on Mac OS X 10.4
by Mark A. Thalman 27 Jul '07

27 Jul '07

We are using the boost interprocess library for some cross-platform interprocess communication. It seems to be working fine on Windows but we are having some issues on the Mac OS (10.4.10, using gcc 4). One thing is that the remove call always deletes the shared memory file, regardless of whether the other process is using it. Does anyone know if this has been tested? Also, the only version I can find is in CVS. Is this where I should be getting the source from, or is there an "official" release somewhere? -- Mark

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[statechart] completion event
by Francisco Santos 27 Jul '07

27 Jul '07

Dear Mr. Andreas Huber, Are completion transitions and events supported by the Statechart Boost library? If so, how do you recommend they should be implemented in code. I have not found examples of statemachines containing transitions *without* explicit triggers in your library's doc page (http://www.boost.org/libs/statechart/doc/index.html) Thank you, Francisco Santos PS: I have included the definition of a completion transition and completion event for reference: A completion transition is a transition without an explicit trigger, although it may have a guard defined. When all transition and entry actions and activities in the currently active state are completed, a completion event instance is generated. This event is the implicit trigger for a completion transition. The completion event is dispatched before any other queued events and has no associated parameters. For instance, a completion transition emanating from a concurrent composite state will be taken automatically as soon as all the concurrent regions have reached their final state. If multiple completion transitions are defined for a state, then they should have mutually exclusive guard conditions. [1] "Completion transitions and completion events", p. 144, Unified Modeling Language Specification, v1.4.2, 2004

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[tests] Signals not well covered in unit tests (in contrast to exceptions)?
by Jens Seidel 27 Jul '07

27 Jul '07

Hi, I have the following problem with a C++ project on Linux using the Boost.test framework: I use the "resource acquisition is initialization" technique to ensure that all resources I allocate are properly released. That's why I have helper classes with a resource allocation in the constructor and deallocation in the destructor. One example of such a helper class is an indentation for my logging code: LOG("blabla"); { LogIndendation indent; // start indentation of output LOG("a message"); divide_by_zero(); LOG("a further message"); } // reset indentation LOG("blabla"); The output is normally: blabla a message a further message blabla Please note that divide_by_zero (which perform an integer division by zero) causes a SIGFPE fatal arithmetic error and the signal handler of Boost.test detects this. Nevertheless the destructor of LogIndendation is *not* called and all further tests I have create wrong indented output (which I compare with the expected output as another test too). So I get: test1 blabla a message unknown location(0): fatal error in "Test1": signal: SIGFPE (arithmetic exception) test2 blabla If I do not generate a signal but throw an exception instead, the destructor is called so this is fine. (Please note that g++ does normally not call a destructor with such a technique if the exception is not catched at all (probably because all resources are expected to be cleaned up, once the process terminates???), but Boost.test catchs all exceptions - good.) I also tried to write my own SIGFPE signal handler which just throws an exception. But this handler is not called, probably it's overwritten by Boost's one. Probably Boost doesn't call the previous handler because it normally terminates the application. But maybe it's possible for Boost to save the initial handler in main() and later to compare the current handler with the initial one. If they are equal handle signals as usual (output an error) otherwise do nothing and call the previous handler? Has anyone a good solution for me, or is there a problem with Boost.test and signals? How to solve this? Jens

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boost 1.34.1 build.bat
by chun ping wang 27 Jul '07

27 Jul '07

For some reason i can no longer specify the toolset to use ...when i run build.bat mingw on my windows machine.. it defaults to msvc. Inside user-config.jam I have using mingw : : C://Dev-Cpp//bin//gcc ; but it keeps using msvc build.

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Any update on a form of boost::threads getting into the C++ 0x standard?
by Graham Reitz 26 Jul '07

26 Jul '07

Our group has had a lot of success with boost::threads and grown comfortable with its use. Thanks, Graham

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Boost with XCode 2.4.1
by Scott Froberg 26 Jul '07

26 Jul '07

Hi All, I'm very new around here. Is anyone using Boost with Apple's XCode 2.4.1? I'm having some trouble with adding the libraries correctly. Thanks, Scott ____________________________________________________________________________________ Get the free Yahoo! toolbar and rest assured with the added security of spyware protection. http://new.toolbar.yahoo.com/toolbar/features/norton/index.php

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[Lambda] Trouble using istreambuf_iterators
by Scott Meyers 26 Jul '07

26 Jul '07

The following code using Lambda with vector iterators compiles without complaint: vector<char> v; find_if(v.begin(), v.end(), _1 == 'x'); Ditto for this code, which uses istream_iterators: istream_iterator<char> b1(cin); istream_iterator<char> e1; find_if(b1, e1, _1 == 'x'); But the same code with istreambuf_iterators gets rejected: istreambuf_iterator<char> b2(cin); istreambuf_iterator<char> e2; find_if(b2, e2, _1 == 'x'); Error messages from VC8 and gcc 4.1.1 are below. Am I doing something wrong, is there a bug in Lambda regarding istreambuf_iterators, or is this a restriction that I didn't see documented somewhere? Thanks, Scott VC8 says: lambda.cpp D:\Apps\Microsoft Visual Studio 8\VC\INCLUDE\algorithm(87) : error C2664: 'bool boost::lambda::lambda_functor<T>::operator ()<char>( A &) const' : cannot convert parameter 1 from 'char' to 'char &' [Instantiation traceback omitted] gcc 4.1.1. says: stl_algo.h:188: error: no match for call to '( boost::lambda::lambda_functor< boost::lambda::lambda_functor_base< boost::lambda::relational_action<boost::lambda::equal_action> , boost::tuples::tuple< boost::lambda::lambda_functor< boost::lambda::placeholder<1> >, const char > > > ) (char)' stl_algo.h: In function 'istreambuf_iterator<char, char_traits<char> > __find_if( istreambuf_iterator<char, char_traits<char> > , istreambuf_iterator<char, char_traits<char> > , boost::lambda::lambda_functor< boost::lambda::lambda_functor_base< boost::lambda::relational_action<boost::lambda::equal_action> , boost::tuples::tuple< boost::lambda::lambda_functor< boost::lambda::placeholder<1> >, const char > > >, input_iterator_tag )': [Instantiation traceback omitted]

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Tuple use/overuse?
by Graham Reitz 26 Jul '07

26 Jul '07

I have been finding that the boost::tuple library is so convenient that I am concerned I may be overusing it. For example, in situations where I might use a struct I am tend to prefer a tuple. Where is a good place to draw the line in situations like this? Or is this the intent to use it as often as possible? Thanks much, Graham

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