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Can i build boost under cygwin?
by Steven Woody 09 Jan '08

09 Jan '08

hi, the building process failed. it reported the libraries was not fully build properly. does boost support cygwin? thanks. -- woody then sun rose thinly from the sea and the old man could see the other boats, low on the water and well in toward the shore, spread out across the current.

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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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