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asio - POSIX.4 Message Queues
by Hite, Christopher 30 Aug '11

30 Aug '11

Any chance of getting support for Posix Message Queues? http://www.users.pjwstk.edu.pl/~jms/qnx/help/watcom/clibref/mq_overview.html How do I make asio listen to a foreign file descriptor to do basic reactor style code? Is this still the way to do things with the posix queues? socket.async_read_some(null_buffers(), read_handler); On a unrelated note: The search feature on boost.org is broken by google. Could we hook it up to bing or yahoo if they don't fix it? Chris

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[units]
by Thomas Taylor 30 Aug '11

30 Aug '11

Could you please review the following patch for inclusion in boost::units? *WHY*: Obviously this only defines a conversion for boost::units::one to a numerical 1. When trying to convert at runtime (aiming for a runtime/dynamic unit instead of the compiletime/static unit provided) I use the following function: template <typename U1, typename U2> double unit_dispatch2t(U1 const& u1, U2 const& u2) { return bu::conversion_factor(u1,u2); } where U1 and U2 are boost::unit::unit derivatives. Without a conversion operator the compiler chickens out by claiming to not be able to convert boost::units::one to (in my case) double. The added conversion operator allows successfull compilation, thus allowing actual runtime units (my application needs to handle calculations where some units are known at compiletime and some only at runtime (e.g. the user wants the calculation to be done in meters or millimeters)). HTH, Thomas --- one.hpp 2011-08-30 09:50:13.000000000 +0200 +++ one2.hpp 2011-08-30 09:50:07.000000000 +0200 @@ -19,3 +19,3 @@ -struct one { one() {} }; +struct one { one() {} operator int() { return 1; } };

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[wave] Tracing a macro in a preprocessor directive
by Edward Diener 30 Aug '11

30 Aug '11

I was trying to trace the output of a macro within a preprocessor directive in a file using the Wave trace facility. The directive is: #elif BOOST_PP_ITERATION_FLAGS() == 1 so I specified: #pragma wave trace(enable) #elif BOOST_PP_ITERATION_FLAGS() == 1 #pragma wave trace(disable) But wave's trace showed me an empty file where the macro output ( -tsomefile ) should have been. Is there a way to capture the output of the BOOST_PP_ITERATION_FLAGS() macro at the point where the #elif is occuring using Wave's trace facility ?

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Asio does not compile
by Alessandro Candini 30 Aug '11

30 Aug '11

My code (simplyfication of this: http://www.boost.org/doc/libs/1_47_0/doc/html/boost_asio/tutorial/tuttimer1…) #include <iostream> #include </usr/local/include/boost/asio.hpp> // Boost version 1.47.0 int main() { return 0; } Compilation command: g++ -Wall -o timer1 timer1.cpp Error: /tmp/ccGUgnoD.o: In function `__static_initialization_and_destruction_0(int, int)': timer1.cpp:(.text+0x52): undefined reference to `boost::system::generic_category()' timer1.cpp:(.text+0x5e): undefined reference to `boost::system::generic_category()' timer1.cpp:(.text+0x6a): undefined reference to `boost::system::system_category()' /tmp/ccGUgnoD.o: In function `boost::asio::error::get_system_category()': timer1.cpp:(.text._ZN5boost4asio5error19get_system_categoryEv[boost::asio::error::get_system_category()]+0x5): undefined reference to `boost::system::system_category()' /tmp/ccGUgnoD.o: In function `boost::asio::detail::posix_tss_ptr_create(unsigned int&)': timer1.cpp:(.text._ZN5boost4asio6detail20posix_tss_ptr_createERj[boost::asio::detail::posix_tss_ptr_create(unsigned int&)]+0x19): undefined reference to `pthread_key_create' /tmp/ccGUgnoD.o: In function `boost::asio::detail::posix_tss_ptr<boost::asio::detail::call_stack<boost::asio::detail::task_io_service>::context>::~posix_tss_ptr()': timer1.cpp:(.text._ZN5boost4asio6detail13posix_tss_ptrINS1_10call_stackINS1_15task_io_serviceEE7contextEED2Ev[_ZN5boost4asio6detail13posix_tss_ptrINS1_10call_stackINS1_15task_io_serviceEE7contextEED5Ev]+0x15): undefined reference to `pthread_key_delete' /tmp/ccGUgnoD.o: In function `boost::asio::detail::posix_tss_ptr<boost::asio::detail::call_stack<boost::asio::detail::strand_service::strand_impl>::context>::~posix_tss_ptr()': timer1.cpp:(.text._ZN5boost4asio6detail13posix_tss_ptrINS1_10call_stackINS1_14strand_service11strand_implEE7contextEED2Ev[_ZN5boost4asio6detail13posix_tss_ptrINS1_10call_stackINS1_14strand_service11strand_implEE7contextEED5Ev]+0x15): undefined reference to `pthread_key_delete' collect2: ld returned 1 exit status make: *** [all] Error 1 Any ideas? 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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[Signals\Signals2] Move semantics
by Szymon Gatner 29 Aug '11

29 Aug '11

Hi, Any plans to do signals\signals2 movable? Just getting used to move things with great boost.move + boost.container libraries and being able to do same with signal-related code would be really nice as now the only way to deal with that is to keep signals on the heap which I find rather awkward. Cheers, Simon

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why aren't I getting multithreaded versions of the libraries that need to be built?
by Ted Byers 29 Aug '11

29 Aug '11

This is in cygwin, using gcc. initially I used the following (I don't use python and don't have MPI, but wanted everything else): $ ./bootstrap.sh --with-libraries=chrono,date_time,exception,filesystem,graph,graph_parallel, iostreams,math,program_options,random,regex,serialization,signals,system,tes t,thread,wave ./b2 install I then tried building QuantLib, which makes extensive use of boost, including the test framework. But it failed because it tried linking to a multihtreaded build of the test frameqwork. I therefore tried the following, assuming that like make, it would just build and install those targets that had not been built the first time. $ ./bootstrap.sh --with-libraries=chrono,date_time,exception,filesystem,graph,graph_parallel, iostreams,math,program_options,random,regex,serialization,signals,system,tes t,thread,wave link=static link=shared threading=single threading=multi ./b2 install Unfortunately, it did not create the multithreaded build of the testframework that QuantLib requires. What did I miss that is preventing me from getting the multihtreaded builds of the required libraries? Thanks Ted

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boost-style yaml parser
by Tim Blechmann 29 Aug '11

29 Aug '11

hi all, i wonder, does anyone have a boost-style parser for yaml? boost.propertytree lists yaml as one of the future parsers, has there been some progress on that? thanks, tim

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Cannot get Wave + Spirit Compile
by Alexander Feldman 29 Aug '11

29 Aug '11

Hi, I have (I suppose) a beginner problem -- cannot make wave + spirit compile. I think there is an iterator problem but I cannot understand the compiler error. I am attaching a small example and the error output - can somebody explain how to fix this? I have searched around a lot but can't find an answer to that. Thanks, -- Alex

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[math][tools][units] generic libraries not generic enough
by alfC 29 Aug '11

29 Aug '11

Hi, Lately I am using Boost.Units quite intensively for defining lots of thermodynamic functions. The other day I needed a root finding algorithm that can work on one of these functions. I look at couple of libraries,and I ended up rolling and adaptor that adimensionalizes the function on Boost.Units quantities, etc, etc. Then I though, hey! we have Boost.Math tools, even root finding algorithms, and these functions are *very* generic as Boost is supposed to be. And I found the function: boost::math::tools::bracket_and_solve_root which has the perfect underlying algorithm for the application. I started programming and after several compilation errors I realized that, as happened before, the functions are not generic enough. For example the arguments are bracket_and_solve_root( F f, const T& guess, const T& factor, bool rising, Tol tol, boost::uintmax_t& max_iter); in my case "guess" is an argument type of type boost::units::quantity<si::meter> but then "factor" has to be a *different* type. For this function to be generic one need that factor is of new type parameter. In my opinion the function should be template<typename F, typename T, typename Fact, typename Tol> bracket_and_solve_root( F f, const T& guess, const T& factor, bool rising, Tol tol, boost::uintmax_t& max_iter); to begin with (and then there is a chain of other internal changes). What do you think? should I open a bug ticket? Let's put it in more abstract way: T*T=T should not be a requirement for a root algorithm to work. Once and for all, can we give a name to the model type of which Boost.Units quantity models for? so the library writers stop assuming that T*T=T for numeric values and can improve half-way generic libraries? Other numeric libraries that suffer from this deficiency are Boost.Accumulators, Boost.Geometry, and Boost.Interval among the ones I tried. I think this issues should be addressed, not only to make them work with Boost.Units but also to bring those libraries to a higher level of generality. Just an opinion. Thank you, Alfredo

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Regarding boost.python build on windows 7 (64 bit) VC9.0
by Nori Vasudeva Pavan Kumar 29 Aug '11

29 Aug '11

Hi I am trying to develop some python applications which use boost.python extensions. I am very new to both VC and Boost. I am able to compile boost.python following the help i found out in google. But I am not able to build my dll library linking with boost libraries. I am not able to figure out what and all going wrong. If I make it static library to be generated, the code builds but my python script is not able to import the library. Could you please direct me to a link where I can find solutions to all the problems regarding building and developing applications using boost.python. Regards, Vasudev

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