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

boost::asio - reason for asio_handler_invoke
by mikpol 08 Jan '08

08 Jan '08

Hi, I've been trying to understand the reasons to have asio_handler_invoke function, and so far I am unable to understand why it is needed. It is used to override invocation policy for a function-like object based on the handler. boost::asio gives one example with using io_service::strand: template<typename F> void asio_handler_invoke(F fun, MyHandler* h) { h->strand.invoke(fun); } My question is why is it needed to make this function templatized on ANY function object, and not just MyHandler? Why can't we just define MyHandler::operator() in terms of strand like this: struct MyHandler { io_service::strand strand. void operator()() { strand.invoke(boost::bind(&MyHandler::private_invoke, this)); } void private_invoke() { // do stuff... } } Thanks for any help. -- View this message in context: http://www.nabble.com/boost%3A%3Aasio---reason-for-asio_handler_invoke-tp14… Sent from the Boost - Users mailing list archive at Nabble.com.

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[multi_index] range selection over composit_key problem
by Kowalke Oliver (QD IT PA AS) 08 Jan '08

08 Jan '08

Hello, I want to do an range selection over an composit key but I get compiler errors like: /home/kowalke/Projects/test_multi_index/src/test_multi_index.cpp:85: instantiated from here /opt/boost/include/boost-1_34/boost/multi_index/ordered_index.hpp:978: error: no match for call to '(boost::tuples::tuple<boost::multi_index::detail::unbounded_type, bool, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>) (boost::multi_index::composite_key_result<boost::multi_index::composite_key<item, boost::multi_index::member<item, double, &item::function>, boost::multi_index::member<item, bool, &item::active>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >)' I've appended a test app. Thanks for advice! regards, Oliver #ifdef HAVE_CONFIG_H #include <config.h> #endif #include <algorithm> #include <iostream> #include <utility> #include <cstdlib> #include <stdexcept> #include <string> #include <boost/foreach.hpp> #include <boost/multi_index_container.hpp> #include <boost/multi_index/member.hpp> #include <boost/multi_index/ordered_index.hpp> #include <boost/multi_index/composite_key.hpp> #include <boost/lambda/lambda.hpp> namespace mi = boost::multi_index; struct item { double function; bool active; item( double function_, bool active_) : function( function_), active( active_) {} }; struct idx_tag {}; typedef mi::multi_index_container< item, mi::indexed_by< mi::ordered_unique< mi::tag< idx_tag >, mi::composite_key< item, mi::member< item, double, & item::function >, mi::member< item, bool, & item::active > >, mi::composite_key_compare< std::greater< double >, std::greater< bool > > > > > table; typedef table::index< idx_tag >::type idx_type; int main( int argc, char *argv[]) { try { table tbl; tbl.insert( item( -1.1, true) ); tbl.insert( item( 1., true) ); tbl.insert( item( 0., true) ); tbl.insert( item( 1.1, false) ); tbl.insert( item( -1., true) ); tbl.insert( item( -1., false) ); idx_type & idx( tbl.get< idx_tag >() ); std::pair< idx_type::iterator, idx_type::iterator > p( idx.range( boost::make_tuple( mi::unbounded, true), boost::make_tuple( boost::lambda::_1 >= 0., true) ) ); for ( ; p.first != p.second; ++p.first) std::cout << p.first->function << " " << std::boolalpha << p.first->active << std::endl; return EXIT_SUCCESS; } catch ( std::exception const& e) { std::cerr << e.what() << std::endl; } catch ( ... ) { std::cerr << "unhandled exception" << std::endl; } return EXIT_FAILURE; }

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Re: [Boost-users] [boost] upcoming Switch library review Jan 5th - Jan 9th
by Stjepan Rajko 07 Jan '08

07 Jan '08

On Jan 6, 2008 7:34 AM, Tobias Schwinger <tschwinger(a)isonews2.com> wrote: > Steven Watanabe wrote: > > Tobias Schwinger <tschwinger <at> isonews2.com> writes: > >> Of course there are no pointers to templates, so using a function > >> pointer for anything but the default is pretty pointless. So is trying > >> to handle varying result types -- maybe the result type should be passed > >> in with another template parameter? > > > > I'd rather leave it as result_of<F()>::type. > > Actually 'result_of<F()>::type' determines the result of the nullary > call to F. I don't think I like this sort of "result_of abuse"... The > correct usage would be 'result_of<F(MPLConstant)>::type' but it's > pointless since 'MPLConstant' varies and so may the whole type expression. > > So, if you insist on deducing the result type from the function object > (instead of having it specified explicitly) my vote is 'F::result_type', > however, I still find another template parameter more appropriate for > the following good reasons: > > o The function object can work fine with result_of in a non-'switch_' > context. The cases can return different things as long as they are > convertible to the result of 'switch_', and > > o there is no way to determine this type with 'result_of. > > The current implementation seems to use result_type - is it planned to change to use result_of? I agree that result_of<F()>::type is slightly abusive, since that's not what actually gets called. Would using result_of<F(boost::mpl::front<Cases>::type)> be an option for a non-empty case sequence? As long as the order of the cases doesn't matter (btw, does it?), the user could put the desired type in the front of the Cases sequence if the return type differs for different MPLConstant types. Stjepan

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Which library my program linked?
by Lizheng 07 Jan '08

07 Jan '08

I download the precompiled static boost librarys from boost-consulting website,I found there is more than one "lib" files for a boost library,for example "regex" library,there exist below ".lib" files: - libboost_regex-vc80-mt-1_34_1.lib; - libboost_regex-vc80-mt-gd-1_34_1.lib; - libboost_regex-vc80-mt-s-1_34_1.lib; - libboost_regex-vc80-mt-sgd-1_34_1.lib; - libboost_regex-vc80-s-1_34_1.lib; - libboost_regex-vc80-sgd-1_34_1.lib; so what is the function of the files?I most use VC8 and MFC to write my program,so which ".lib" file my program linked?If I want my program to link with a boost dll library,how can I do?

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thread strange
by Chameleon 07 Jan '08

07 Jan '08

I have a strange problem with the code below. >From outside the function operator()(), I can have the pointer to thread object 'thread'. >From inside operator()() 'thread' is always 0. Why does this happen? ------------------------------------------------------------------ #include <cstdio> #include <boost/thread/thread.hpp> class A { boost::thread *thread; public: A() : thread(0) {} ~A() { join(); } void createThread() { thread = new boost::thread(*this); } void operator()() { printf("Starting thread with pointer: %d\n", thread); //<<<<<<<<<<<<<<HERE! delete thread; thread = 0; } void join() { if (thread) thread->join(); } }; int main(int, char**) { A a; a.createThread(); a.join(); return 0; } ------------------------------------------------------------------

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MSVC2005/icc10.1 boost::date_time std::max 1.34.1
by Hicham Mouline 07 Jan '08

07 Jan '08

hello, #include <iostream> #include <algorithm> int main() { const double d = std::max(5.0, 6.0); return 0; } This works fine. <algorithm> is supposed to be included to use the max algorithm. <algorithm> comes with VisualC++ headers, which intel uses. The strange thing is that when adding #include <boost/date_time/posix_time/posix_time.hpp> before or after <algorithm> #include <iostream> #include <algorithm> #include <boost/date_time/posix_time/posix_time.hpp> int main() { const double d = std::max(5.0, 6.0); return 0; } 1>.\main.cpp(9): error: expected an identifier 1> const double d = std::max(5.0, 6.0); 1> ^ 1> 1>.\main.cpp(9): error: expected an identifier 1> const double d = std::max(5.0, 6.0); Inclusing of that header seems somehow to damage "max". Gcc4.1/boost doesn't have this problem. any ideas, rds,

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[log] Boost Logging v2 - new version (v0.13.6)
by John Torjo 07 Jan '08

07 Jan '08

Boost Logging v2 - new version (v0.13.6) The Boost Logging Lib v2 is getting closer and closer to its review (Feb 4). I've just released a new version, lots of new features: * added tags (attributes a logged message can have, like : line & file, function name, time, etc.) * scoped logs * caching messages before logs are initialized * high precision time (as tag as well) * added spacer formatter - you can specify what goes before and after your formatter * new formatter: named_spacer : Allows you to contain multiple formatters. You have a spacer string, and within it, you can escape your contained formatters * new destination : named - like named_spacer, but for destinations All in all, I've added quite a few features - so, take a look! Look forward to your feedback! http://www.torjo.com/log2/ http://torjo.blogspot.com/2008/01/boost-logging-v2-new-version-v0136.html Best, John -- http://John.Torjo.com -- C++ expert ... call me only if you want things done right

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TestUnit - builing hierarchical tests
by Tomasz Kalkosiński 07 Jan '08

07 Jan '08

Hello group. I want to use Boost.UnitTest library for my code testing. I went thru examples and I've found it useful and easy. It's easy on simple one-method one-file examples. My problem begun when I wanted to build few hierarchical test suites splitted into directories and files. I failed. There is no example on boost page - how to write them splitted in a few files. Only cases are pointers to functions in one file. I had problems including unit test header - I had multiple definitions of boost classes. When i removed header - there were no macros etc. Can anyone share a good practice - how to wrap example1 and example2 to one mainsuite? And use 3 files for it? Examples from tutorial: http://www.pdc.kth.se/training/Talks/C++/boost/libs/test/doc/components/uni… On a side note I find myself disappointed with Boost.UnitTest documentation. It isn't easy to follow (like I did for example with Boost.Regex) . Links to examples are broken on main site : http://www.boost.org/libs/test/doc/components/utf/index.html. But there's a mirror on http://www.pdc.kth.se/training/Talks/C++/boost/libs/test/doc/components/uni…. That's nice, but their latest revision is more than 4 years old! But when you google enough you find another one - author's own - on http://www.patmedia.net/~rogeeff/html/ revised 2007 (at least copyright is 2007). Is it the way Boost library documentation is meant to be? On a second side note I had no "main ()" function problem on debian. There were changes on 1.34.0 so it won't work anymore as documentation says. So I had to dig thru bug reports, mailing lists to find out author's personal note on these changes. As a library user I don't want to waste time googling, I want to use documentation and get it working. I belive Boost.UnitTest is a good work so don't waste it on a poor support! Greetings, Tomasz Kalkosiński

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statechart null in_state_reaction
by Sean Kelly 06 Jan '08

06 Jan '08

Hello, I would like to implement a null-op in_state_reaction - The in_state_reaction template requires a action argument whereas the transition to self doesn't - Which is the preferred method ? Thanks Sean

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Program_options - allowing unknown options in configuration file
by Raul Pedro Santos 06 Jan '08

06 Jan '08

Hi everyone. I'm new to Boost and program_options in particular but so far it has been a joy working with the various boost libraries. Thanks to all the developers for their hard work! I'm using program_options to parse a configuration file but I need to have some options that are not described with program_options. Specifically, I need to use the same file for both my program configuration and also for configuring log4cxx. Each line of log4cxx configuration is of the form "log4j.option=value" and I can't limit the options that can be added to the program, so I can't describe them and ignore them afterwards. I know this is possible on the command line, by calling allow_unregistered() but I need the same thing for a config file, which I can't find out how to do anywhere. Can someone point me in the right direction, please? Thanks in advance. Raul PS - Happy New Year, everyone! :-) ____________________________________________________________________________________ Looking for last minute shopping deals? Find them fast with Yahoo! Search. http://tools.search.yahoo.com/newsearch/category.php?category=shopping

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Re: [Boost-users] cannot build the regex example in visual c++ 2008
by David Randolph Palmer 06 Jan '08

06 Jan '08

I too am having a similar problem, here is my output; c:\Program Files\boost\boost_1_34_1>bjam --with-regex stage msvc-9.0 c:/Program Files/boost/boost_1_34_1/tools/build/v2/tools\msvc.jam:270: in config ure-really *** argument error * rule path.make ( native ) * called with: ( ) * missing argument native c:/Program Files/boost/boost_1_34_1/tools/build/v2/util\path.jam:46:see definiti on of rule 'make' being called c:/Program Files/boost/boost_1_34_1/tools/build/v2/tools\msvc.jam:145: in config ure c:/Program Files/boost/boost_1_34_1/tools/build/v2/tools\msvc.jam:116: in msvc.i nit c:/Program Files/boost/boost_1_34_1/tools/build/v2/build\toolset.jam:27: in usin g C:\Users\dad\user-config.jam:30: in modules.load c:/Program Files/boost/boost_1_34_1/tools/build/v2\build-system.jam:95: in load- config c:/Program Files/boost/boost_1_34_1/tools/build/v2\build-system.jam:143: in load c:\Program Files\boost\boost_1_34_1\tools\build\v2/kernel\modules.jam:261: in im port c:\Program Files\boost\boost_1_34_1\tools\build\v2/kernel/bootstrap.jam:132: in boost-build c:\Program Files\boost\boost_1_34_1\boost-build.jam:9: in module scope I read through msvc.jam and there is no reference to v9. It appears to default and the default settings don't work. I am also using the express edition of v9. Any help appreciated! chris briscoe wrote: > > Hi, whitespace was an issue - thanks. > > using this command: bjam --with-regex stage msvc-9.0 didn't work, > produced > a lot of output > then appeared to skip everything for lack of stage\lib. > > I tried this from the boost root > > C:\Program Files\boost\boost_1_34_1> bjam ^ > More? --build-dir=C:\temp\build-boost ^ > More? --toolset=msvc-9.0 stage > > this ground away for an age producing reams of output and finished with > the > result attached. > > Still don't seem to be there. > > > Thanks > Chris > > ----- Original Message ----- > From: "John Maddock" <john(a)johnmaddock.co.uk> > To: <boost-users(a)lists.boost.org> > Sent: Friday, January 04, 2008 7:24 PM > Subject: Re: [Boost-users] cannot build the regex example in visual c++ > 2008 > > >> chris briscoe wrote: >>> Hi, >>> thanks very much for responding. >>> I have followed your instructions but so far can't get it to work. >>> >>> running bjam as below gives a message: >>> msvc:9.0:C:/microsoft..../bin/cl.exe.jam: Invalid argument >>> and : >>> rule msvc:9.0:c:/micro..../cl.exe.init unknown in module toolset >>> then appears to drop through with a number of in (various modules) >>> messages. >>> >>> Would greatly appreciate your help. >> >> Please post the complete error messages, plus your user-config.jam >> changes, >> otherwise it's hard to say. However... at a guess it appears that there >> isn't any whitespace between the arguments in your user-config.jam. >> Unfortunately bjam insists on whitespace around separators like ":" so: >> >> using msvc :9.0:path-to-cl; >> >> will *not* work, but: >> >> using msvc : 9.0 : path-to-cl ; >> >> will. >> >> HTH, John. >> >> _______________________________________________ >> Boost-users mailing list >> Boost-users(a)lists.boost.org >> http://lists.boost.org/mailman/listinfo.cgi/boost-users >> > > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users > -- View this message in context: http://www.nabble.com/cannot-build-the-regex-example-in-visual-c%2B%2B-2008… Sent from the Boost - Users mailing list archive at Nabble.com.

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cannot build the regex example in visual c++ 2008
by chris briscoe 06 Jan '08

06 Jan '08

Hello- absolute beginner here. I have the latest (November version) of visual studio c++ 2008 express. The header only version compiled fine. However the regex example fails with many unresolved external symbols. Do I need to build the libraries for this compiler? Or am I making some other booboo. I have had a go - following the instructions but so far without success. Grateful for any help. Chris Briscoe

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Re: [Boost-users] upcoming Switch library review Jan 5th - Jan 9th
by dan marsden 06 Jan '08

06 Jan '08

Stjepan Rajko wrote: > If you are interested, please consider submitting a review of this > library. I will send more detailed instructions on what to include in > the review on the 5th. Can I jump the gun with with a few questions please? Why is the fall through behaviour to throw an exception? This is not consistent with standard switch, possibly a motivation section is needed in the docs to explain this type of decision? I'm not too clear with the documentation what the parameter 'n' can be? It is of type 'Int' which is described as being an Integer in the parameters section of the documentation. What does this mean, any built in integral type, can I switch on a std::string? What are the limitations? I got a bit lost here in the docs here, after admittedly only a quick read. Maybe just some clarification is required? The parameter section does not specify the arities of the 2 function object parameters, I had to deduce them from the example. Why do these have to be function objects, and not just any callable type, including ordinary functions (using the Boost.ResultOf mechanism to sort out the return type)? I'm not sure how useful that would be for 'f', but for 'default_' a full blow function object seems a bit much typing, can't I just use a function. Also, why is 'default_' unary, the default in a standard switch statement does not access the switch parameter, and the example does not exploit this feature either. Why not just a nullary function? Again some motivation might be nice. And finally, as the introduction mentions the efficiency of the standard switch statement, could the docs show some performance stats for the library code for comparison? Cheers Dan ___________________________________________________________ Yahoo! Answers - Got a question? Someone out there knows the answer. Try it now. http://uk.answers.yahoo.com/

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Switch library review begins today and ends on Jan 9th
by Stjepan Rajko 05 Jan '08

05 Jan '08

The review of the Switch library by Steven Watanabe begins today. Description: The built in C/C++ switch statement is very efficient. Unfortunately, unlike a chained if/else construct there is no easy way to use it when the number of cases depends on a template parameter. The Switch library addresses this issue. You can download the library from the Boost Vault: http://tinyurl.com/23qn7w For convenience, the docs have been uploaded here: http://tinyurl.com/2h6ut9 ... and the source file here: http://tinyurl.com/2cbfyk 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 to Dan Marsden, Larry Evans, Tobias Schwinger, and Alexander Nasonov for already opening up the discussion in the following threads: http://tinyurl.com/2u6fjr [nabble/boost-user] http://tinyurl.com/267uj3 [nabble/boost-dev] Thank you for taking the time to look into this library, and I hope that some of you will be able to provide a full review for it. Regards, Stjepan

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[Boost.MPL and Boost.Fusion] Combinatorial game with typelists
by dariomt＠gmail.com 05 Jan '08

05 Jan '08

Hello boost users, I need some advice in using MPL and fusion. Lets take the following case for a typical Factory pattern (full compilable source code is attached): class Base {...}; class Factory {...}; template <typename T> struct Helper {...}; // constructor registers creation function for template parameter Now we have a template defining a family of derived classes: template <typename U, typename V, typename W> class DerivedUVW : public Base {...}; And a helper registration macro: #define HELPER_DERIVED_UVW(U, V, W) \ Helper<DerivedUVW<U, V, W> > BOOST_PP_CAT(h, __LINE__) (#U #V #W); And all possible U V and W classes in the combination game: struct A1 {}; struct A2 {}; // for U struct B1 {}; struct B2 {}; // for V struct C1 {}; struct C2 {}; // for W Now with manual registration its just a matter of patience: // Manual registration: // must type all possible combinations -> ugly HELPER_DERIVED_UVW(A1, B1, C1); HELPER_DERIVED_UVW(A1, B1, C2); // etc... To create the desired object just use Factory::instance().create("A1B1C1")->doInterestingStuff() And now the six million dollar question: Is there a way in which MPL and fusion can automatically do the registration? Here registration means the instantiation of template Helper with all possible combinations of DerivedUVW with elements from lists like: typedef boost::mpl::vector<A1,A2> Ulist; typedef boost::mpl::vector<B1,B2> Vlist; typedef boost::mpl::vector<C1,C2> Wlist; and registered with an appropiate name like "A1B1C1" Of course the objective is to easily add A3, A4, B3, C4, etc... to allow more combinations, without having to manually update all the registration code, ideally just the typelists. And, let's not forget variants DerivedUV or DerivedUVWZ with a different number of template parameters. I'm trying to think how I would do combinations for values in runtime and translate it to the MPL domain. Still no success. Any help, suggestions or comments will be appreciated. PS: the context of this problem is being able to expose a heavily templatized library to a user selecting the combination of template classes at runtime with a text string. I'm sure there's a suitable solution to this problem somewhere out there, or at least some hints to build my own solution...

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Regex: Question about greedy/non-greedy precedence
by Arne Babnik 05 Jan '08

05 Jan '08

Hello, I'm using boost::regex 1.34.0 and experience behaviour with mixed greedy and non-greedy operators in the same expression which I do not understand. I have either one of the following input strings: user1(a)hostname.com user2 and want to keep only the usernames, so I use the following expression: (.*?)(@.*)? with the format string $1. I would expect that basically the regex machine would first try to satisfy the greedy operator "?", and then fill up the non-greedy "*?" with the remaing part of the input. However, the following does NOT work (the hostname is not removed): std::string output; output = boost::regex_replace(std::string("user1(a)hostname.com"), boost::regex("(.*?)(@.*)?"), std::string("$1"), boost::regex_constants::format_first_only); However, if I omit the "format_first_only", it works as expected. What do I miss? Thanks, Arne ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program.

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base 64 encoding
by Eames, Andrew 04 Jan '08

04 Jan '08

Hi, I'm trying to encode base64 data by composing base64_from_binary with transform_width but this doesn't appear to work correctly when the data is not a multiple of 3 long. What is the correct way to handle this - do I have to handle the padding myself by extending the input data and then patching the tail of the result? Thanks Andrew

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Serialization and polymorphism
by Ricardo Mayerhofer 04 Jan '08

04 Jan '08

Hi all, I'm trying to find a way to use Boost serialization with polymorphism but wasn't able to make it so far. E.g. I have an abstract class named ILog and two classes that inherits from it. Now I have a vector of ILog. How do I serialize this vector? Thanks. Ricardo

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Re: [Boost-users] base 64 encoding
by Chad Walters 04 Jan '08

04 Jan '08

The simplest workaround would probably be to pad the encoded output to a multiple of 3 by adding 0, 1, or 2 '=' characters as needed. Eames, Andrew" <andrew(a)cognex.com> wrote: But there is still the problem with running off the end of the source - If the source is not a multiple of 3 bytes then the input iterator will run off the end of the input sequence which can cause an error. Andrew

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Re: [Boost-users] [Boost.MPL and Boost.Fusion] Combinatorial gamewith typelists
by dariomt＠gmail.com 04 Jan '08

04 Jan '08

Tobias Schwinger wrote: > Here's an MPL-based solution. Whoa! Thanks a lot! > compiles with GCC4 For me it also works with VS2003 Right now I'm still scratching my head in astonishment ;) I'll definitely come back looking for some more help to understand your solution. Thanks again.

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[date-time] Fwd: Problems when constructing time_duration and ptime from string
by Filip Konvička 04 Jan '08

04 Jan '08

-----Original Message----- From: Kahánek Petr Sent: Friday, January 04, 2008 10:22 AM To: 'boost-users(a)lists.boost.org' Subject: Problems when constructing time_duration and ptime from string Hi, It seems there are problems with duration/ptime construction from string, no matter if one uses duration_from_string, time_from_string or operator >>. Lets have the following code. Using Windows XP service pack 2, MSVS2005 SP 1, Boost 1-34.1 #include <string> #include <boost/date_time/posix_time/posix_time.hpp> using namespace std; using namespace boost; using namespace boost::posix_time; int _tmain(int argc, _TCHAR* argv[]) { string str; time_duration td; ptime time; // try to construct duration and ptime from string where there's no blank space between date and time // 1) duration_from_string will pass // 2) "time_duration >>" will pass // 3) time_from_string will throw // 4) "ptime >>" will pass str = "2007-01-2010:00:05"; td = duration_from_string(str); cout << "\"" << str << "\" == " << to_simple_string(td) << endl; stringstream ss(str); ss >> td; cout << "\"" << str << "\" == " << to_simple_string(td) << endl; try { time = time_from_string(str); cout << "\"" << str << "\" == " << time << endl; } catch(exception& e) { cout << "time_from_string could not construct time from \"" << str << "\", " << e.what() << endl; } try { stringstream ss(str); ss >> time; cout << "\"" << str << "\" == " << time << endl; } catch(exception& e) { cout << "operator >> could not get time from '" << "', " << e.what() << endl; } cout << endl << endl; // try to construct duration and ptime from "2007-01-20-1.xwerf" (mangled delimiters, rubbish in place of // fractional sec.) --> none will throw str = "2007-01-20-1.xwerf"; td = duration_from_string(str); cout << "\"" << str << "\" == " << to_simple_string(td) << endl; stringstream ss2(str); ss2 >> td; cout << "\"" << str << "\" == " << to_simple_string(td) << endl; time = time_from_string(str); cout << "\"" << str << "\" == " << time << endl; stringstream ss3(str); ss3 >> time; cout << "\"" << str << "\" == " << time << endl; cout << endl << endl; // try to construct duration and ptime from "2007.01.20.1.xwerf" (mangled delimiters, rubbish in place of // fractional sec.) --> none will throw str = "2007.01.20.1.0xwerf"; td = duration_from_string(str); cout << "\"" << str << "\" == " << to_simple_string(td) << endl; stringstream ss4(str); ss4 >> td; cout << "\"" << str << "\" == " << to_simple_string(td) << endl; time = time_from_string(str); cout << "\"" << str << "\" == " << time << endl; ss4 >> time; cout << "\"" << str << "\" == " << time << endl; cout << endl << endl; // try to construct duration and ptime from "2008-01-03" // none will throw, duration created although delimiter is "-", ptime created incorrectly str = "2008-01-03"; td = duration_from_string(str); cout << "\"" << str << "\" == " << to_simple_string(td) << endl; stringstream ss5(str); ss5 >> td; cout << "\"" << str << "\" == " << to_simple_string(td) << endl; str = "2008-01-03"; time = time_from_string(str); cout << "\"" << str << "\" == " << time << endl; stringstream ss6(str); ss6 >> time; cout << "\"" << str << "\" == " << time << endl; // even if duration is constructed, printing it to cout with operator << without conversion to string // will assert in strftime.c if hours are out of scope [0,23], or if minutes/seconds are out of [0,59] cout << str << " == " << td << endl; // CRASH return 0; } Output from this program: "2007-01-2010:00:05" == 2007:34:30 "2007-01-2010:00:05" == 2007:34:30 time_from_string could not construct time from "2007-01-2010:00:05", bad lexical cast: source type value could not be interpreted as target "2007-01-2010:00:05" == not-a-date-time "2007-01-20-1.xwerf" == 2007:01:20.100000 "2007-01-20-1.xwerf" == 2007:01:20.100000 "2007-01-20-1.xwerf" == 2007-Apr-13 15:01:20.100000 "2007-01-20-1.xwerf" == 2007-Apr-13 15:01:20.100000 "2007.01.20.1.0xwerf" == 2007:01:20.100000 "2007.01.20.1.0xwerf" == 2007:01:20.100000 "2007.01.20.1.0xwerf" == 2007-Apr-13 15:01:20.100000 "2007.01.20.1.0xwerf" == 2007-Apr-13 15:01:20.100000 "2008-01-03" == 2008:01:03 "2008-01-03" == 2008:01:03 "2008-01-03" == 2008-Mar-26 16:01:03 "2008-01-03" == 2008-Mar-26 16:01:03 ..and then it will assert on cout << td. Durations that have hours out of [0,23] or min/sec out of [0,59] are parsed successfully but cannot be printed to cout using << (assert in strftime.c). Workaround for "pure date", e.g. "2007-01-10", is to append "0" to it. "2007-01-10 0" is parsed OK. I guess these can be considered bugs? Br, Petr

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Help to design a thread server for boost::thread_group seems useless
by lemmel lemmel 04 Jan '08

04 Jan '08

It seems that thread_group doesn't perform any task after the thread termination (see http://thread.gmane.org/gmane.comp.lib.boost.user/5694) and then doesn't manage the memory. So the following code : ------------------------- CODE --------------------------- BEGIN ----------------------- #include #include class Toto { public: Toto(){std::cout << "I'm builded\n";} Toto(const Toto&){std::cout << "I'm builded\n";} void operator() () {std::cout << "I'm called\n";} ~Toto(){std::cout << "I'm destructed\n";} }; int main(int, char **) { boost::thread_group thread; while (true) { thread.create_thread(Toto()); sleep(1); } thread.join_all(); return EXIT_SUCCESS; } ------------------------- CODE --------------------------- END ----------------------- consumes endlessly a finite memory. How can I do in order to free the memory after the thread termination ? I can't use the join/join_all for at the same time I may need to create other threads (e.g. a tcp socket server), and I can't know if a thread is running or not (there is no such methods in the thread class, http://www.boost.org/doc/html/boost/thread.html) _________________________________________________________________ Microsoft vous recommande de mettre à jour Internet Explorer. http://specials.fr.msn.com/IE7P25

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Problems when constructing time_duration and ptime from string
by Kahánek Petr 04 Jan '08

04 Jan '08

Hi, It seems there are problems with duration/ptime construction from string, no matter if one uses duration_from_string, time_from_string or operator >>. Lets have the following code. Using Windows XP service pack 2, MSVS2005 SP 1, Boost 1-34.1 #include <string> #include <boost/date_time/posix_time/posix_time.hpp> using namespace std; using namespace boost; using namespace boost::posix_time; int _tmain(int argc, _TCHAR* argv[]) { string str; time_duration td; ptime time; // try to construct duration and ptime from string where there's no blank space between date and time // 1) duration_from_string will pass // 2) "time_duration >>" will pass // 3) time_from_string will throw // 4) "ptime >>" will pass str = "2007-01-2010:00:05"; td = duration_from_string(str); cout << "\"" << str << "\" == " << to_simple_string(td) << endl; stringstream ss(str); ss >> td; cout << "\"" << str << "\" == " << to_simple_string(td) << endl; try { time = time_from_string(str); cout << "\"" << str << "\" == " << time << endl; } catch(exception& e) { cout << "time_from_string could not construct time from \"" << str << "\", " << e.what() << endl; } try { stringstream ss(str); ss >> time; cout << "\"" << str << "\" == " << time << endl; } catch(exception& e) { cout << "operator >> could not get time from '" << "', " << e.what() << endl; } cout << endl << endl; // try to construct duration and ptime from "2007-01-20-1.xwerf" (mangled delimiters, rubbish in place of // fractional sec.) --> none will throw str = "2007-01-20-1.xwerf"; td = duration_from_string(str); cout << "\"" << str << "\" == " << to_simple_string(td) << endl; stringstream ss2(str); ss2 >> td; cout << "\"" << str << "\" == " << to_simple_string(td) << endl; time = time_from_string(str); cout << "\"" << str << "\" == " << time << endl; stringstream ss3(str); ss3 >> time; cout << "\"" << str << "\" == " << time << endl; cout << endl << endl; // try to construct duration and ptime from "2007.01.20.1.xwerf" (mangled delimiters, rubbish in place of // fractional sec.) --> none will throw str = "2007.01.20.1.0xwerf"; td = duration_from_string(str); cout << "\"" << str << "\" == " << to_simple_string(td) << endl; stringstream ss4(str); ss4 >> td; cout << "\"" << str << "\" == " << to_simple_string(td) << endl; time = time_from_string(str); cout << "\"" << str << "\" == " << time << endl; ss4 >> time; cout << "\"" << str << "\" == " << time << endl; cout << endl << endl; // try to construct duration and ptime from "2008-01-03" // none will throw, duration created although delimiter is "-", ptime created incorrectly str = "2008-01-03"; td = duration_from_string(str); cout << "\"" << str << "\" == " << to_simple_string(td) << endl; stringstream ss5(str); ss5 >> td; cout << "\"" << str << "\" == " << to_simple_string(td) << endl; str = "2008-01-03"; time = time_from_string(str); cout << "\"" << str << "\" == " << time << endl; stringstream ss6(str); ss6 >> time; cout << "\"" << str << "\" == " << time << endl; // even if duration is constructed, printing it to cout with operator << without conversion to string // will assert in strftime.c if hours are out of scope [0,23], or if minutes/seconds are out of [0,59] cout << str << " == " << td << endl; // CRASH return 0; } Output from this program: "2007-01-2010:00:05" == 2007:34:30 "2007-01-2010:00:05" == 2007:34:30 time_from_string could not construct time from "2007-01-2010:00:05", bad lexical cast: source type value could not be interpreted as target "2007-01-2010:00:05" == not-a-date-time "2007-01-20-1.xwerf" == 2007:01:20.100000 "2007-01-20-1.xwerf" == 2007:01:20.100000 "2007-01-20-1.xwerf" == 2007-Apr-13 15:01:20.100000 "2007-01-20-1.xwerf" == 2007-Apr-13 15:01:20.100000 "2007.01.20.1.0xwerf" == 2007:01:20.100000 "2007.01.20.1.0xwerf" == 2007:01:20.100000 "2007.01.20.1.0xwerf" == 2007-Apr-13 15:01:20.100000 "2007.01.20.1.0xwerf" == 2007-Apr-13 15:01:20.100000 "2008-01-03" == 2008:01:03 "2008-01-03" == 2008:01:03 "2008-01-03" == 2008-Mar-26 16:01:03 "2008-01-03" == 2008-Mar-26 16:01:03 ..and then it will assert on cout << td. Durations that have hours out of [0,23] or min/sec out of [0,59] are parsed successfully but cannot be printed to cout using << (assert in strftime.c). Workaround for "pure date", e.g. "2007-01-10", is to append "0" to it. "2007-01-10 0" is parsed OK. I guess these can be considered bugs? Br, Petr

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boost::shared_ptr and casting operation
by Michael Bradley Jr 04 Jan '08

04 Jan '08

Hi, can someone please provide me an elegant way to solve the current problem. class A; class B : public A; boost::shared_ptr<A> pA; boost::shared_ptr<B> pB; Would like to cast pB to pA with a construct like the *static_cast* but that ain't really pretty ! Thanks in advance Michael

4 3

Seg Fault using pool_allocator
by Nindi Singh 04 Jan '08

04 Jan '08

I am getting a seg fault on running the following code. _______________________________________________________________________ #include<map> #include<vector> #include<boost/pool/pool_alloc.hpp> typedef std::vector<double,boost::pool_allocator<double > > vector; int main() { std::map<unsigned long, vector> theStdMap; theStdMap[0]; } _________________________________________________________________________ I am using Ubuntu 7.10 AMD64 g++4.1 and g++4.2 boost 1.34.1 ___________________________________________________________ Yahoo! Answers - Got a question? Someone out there knows the answer. Try it now. http://uk.answers.yahoo.com/

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