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[Proto] Detecting if a tag is a proto type or not
by Joel Falcou 17 Nov '08

17 Nov '08

I want to do some dispatching based on the fatc that my binary_expr tag is one of predefined proto tag or not. What kind of internal properties of proto tags can I try to use to perform this discrimination ? Thanks in advance

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Some problems about GIL
by blp330 17 Nov '08

17 Nov '08

Hi, 1. Does any one know how to crop a image using GIL? 2. The IO extension seems not support to serialize a image binary data to memory, how to do that using GIL? (read png -> do some stuffs... -> write png to char* buffer not file.) 3. Is there any one good performance image comparison algorithm to compare two images by GIL? I am using ImageMagick to do that now. It try to compute Mean Absolute Error for two images, how this can be done by GIL? Thanks for your answer, I am try to adopt my old ImageMagick's code to GIL, I like elegant design of GIL but I am a newbie. Thanks for you patient to answer my questions. :) -- View this message in context: http://www.nabble.com/Some-problems-about-GIL-tp20526156p20526156.html Sent from the Boost - Users mailing list archive at Nabble.com.

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--layout=system in user-config.jam?
by Raymond Wan 17 Nov '08

17 Nov '08

Hi all, In a recent post (a few weeks ago), someone asked if it is possible to remove the compiler name/version from the library name. i.e., libboost_math_c99-gcc43-mt-1_37.so --> libboost_math_c99-mt.so Someone replied that adding "--layout=system" to bjam would do the trick and indeed, that worked. When compiling Boost, I was wondering if it is possible to add this parameter to the user-config.jam file, rather than editting the Makefile directly? If so, what would be the syntax to do this? Somewhere, I read that user-config.jam "define[s] available toolsets" -- I guess this parameter is not a toolset, so it is not possible? The reason I am asking is rather silly -- but just that editting the Makefile is slightly more error-prone than sending a user-config.jam to someone (or backing it up myself for later use) since the Makefile could change based on what configure outputs. Thank you! Ray

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[Proto] Strange behavior with semantic action and custom tag function
by Joel Falcou 16 Nov '08

16 Nov '08

I'm stuck on some problem that may en dup silly. I have a DSL defined by the following grammar : struct dimen_grammar : bp::or_< ////////////////////////////////////////////////////////////////////////// // Terminals are dimensional values or integral values ////////////////////////////////////////////////////////////////////////// bp::or_< bp::terminal< dimensions<bp::_,bp::_> > , integer_grammar > ////////////////////////////////////////////////////////////////////////// // dimen can be added together or scaled by an integer // or shifted left or right by an integer ////////////////////////////////////////////////////////////////////////// ,bp::or_< bp::plus<dimen_grammar,dimen_grammar> ,bp::multiplies<dimen_grammar,integer_grammar> ,bp::multiplies<integer_grammar,dimen_grammar> ,bp::shift_left<dimen_grammar,integer_grammar> ,bp::shift_right<dimen_grammar,integer_grammar> > > {}; I've defined a proper callable_context that take care of my special terminals and built a terminal class. At this point, everythign works perfect : i can build expressions and evaluate them. Now I add a grammar with semantic action that helps me computes an aspect of those expression : struct dimen_size : bp::or_< ////////////////////////////////////////////////////////////////////////// // dimensionnal values terminal contains its own size value ////////////////////////////////////////////////////////////////////////// bp::when< bp::terminal< dimensions<bp::_,bp::_> > , dimension_of< bp::_value>() > ////////////////////////////////////////////////////////////////////////// // integral values has a size of 1 ////////////////////////////////////////////////////////////////////////// , bp::when<integer_grammar, bm::size_t<1>()> ////////////////////////////////////////////////////////////////////////// // size(d1+d2) = max(size(d1),size(d2)) ////////////////////////////////////////////////////////////////////////// , bp::when< bp::plus<dimen_grammar,dimen_grammar> , bm::max<dimen_size(bp::_left),dimen_size(bp::_right)>() > ////////////////////////////////////////////////////////////////////////// // size(d1*i) = size(d1) ////////////////////////////////////////////////////////////////////////// , bp::when< bp::multiplies<dimen_grammar,integer_grammar> , dimen_size(bp::_left) > ////////////////////////////////////////////////////////////////////////// // size(i*d2) = size(d2) ////////////////////////////////////////////////////////////////////////// , bp::when< bp::multiplies<integer_grammar,dimen_grammar> , dimen_size(bp::_right) > ////////////////////////////////////////////////////////////////////////// // size(d1<<i) = size(d1) ////////////////////////////////////////////////////////////////////////// , bp::when< bp::shift_left<dimen_grammar,integer_grammar> , dimen_size(bp::_left) > ////////////////////////////////////////////////////////////////////////// // size(d1>>i) = size(d1) ////////////////////////////////////////////////////////////////////////// , bp::when< bp::shift_right<dimen_grammar,integer_grammar> , dimen_size(bp::_left) > ////////////////////////////////////////////////////////////////////////// // Other returns 0 ////////////////////////////////////////////////////////////////////////// , bp::when<bp::_, bm::size_t<0>()> > {}; This works. If I remove the bp::when<bp::_, bm::size_t<0>()>, it fails to compile when I try to use a hand-overloaded operator<< for displaying expression values on standard output. So, is there anything I missed (like deactivating operator<< in the grammar somehow ?) ? Other question : When defining custom tag to build new function, why does the make_expr tempalte doesn't do check on its argument to see if it's match the grammar of the domain it's bound to use ? Seems I'm forced to add additional layer of SFINAE to prevent those function to get called on w/e types. Thanks in advance for help -- ___________________________________________ Joel Falcou - Assistant Professor PARALL Team - LRI - Universite Paris Sud XI Tel : (+33)1 69 15 66 35

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[asio] Header ordering problems
by Robert Ramey 16 Nov '08

16 Nov '08

#include <boost/date_time/posix_time/posix_time.hpp> #include <boost/asio.hpp> produces the error message at compile time: 1>c:\boost_1_37_0\boost\asio\detail\socket_types.hpp(27) : fatal error C1189: #error : WinSock.h has already been included while #include <boost/asio.hpp> #include <boost/date_time/posix_time/posix_time.hpp> does not. Same problem occurs when including any of the headers in boost/thread/... Robert Ramey

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About boost::asio
by Ken zhang 16 Nov '08

16 Nov '08

Hi Dear all I want to handle socket close event in my connection, but I can't found mothed in ip::tcp::socket,How can I handle close event for socket? Thanks -- Best Regards, Yours Kennir

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library name for boost 1.36
by Alain Leblanc 16 Nov '08

16 Nov '08

Hi, I just built boost 1.36 for the mac and all the library names have xgcc40 inserted in the middle, such as libboost_iostreams-xgcc40-mt-1_36.dylib. It breaks my makefiles that contain the option " -lboost_iostreams". Is there a reason for the xgcc40 in this version and not the others, and is there a way to instruct bjam not to include it in the filename. Thank, s

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[iostreams] How to overload the flush on a outpou stream
by vicente.botet 16 Nov '08

16 Nov '08

Hi, I want to to take a specific action when I flush an output stream. Can Boost.Iostreams be of any use? Thanks is advanve, Vicente

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get_posix_category in boost 1.36
by Daniel França 16 Nov '08

16 Nov '08

Hi people, I got an error of undefined get_posix_category in Boost 1.36, I found this article: http://blog.cplusplus-soup.com/2008/11/boost-c-library-patches-1360.htmlthat tell me that there's no get_posix_category on Boost 1.36: *Boost.System's Missing 'get_posix_category'* In Boost 1.36.0, Boost.System's get_posix_category function had been removed. For strict backwards compatibility, it has to be put in to let older versions of libraries that use the function to link properly. This has been submitted as issue (with patches attached) That's why I cant compile the asynchronous TCP Server example, I tried to get the patch but itsn't online anymore, anyone know how can I solve that? Best Regards, -- Daniel C. França Tecnosapiens: http://tecnosapiens.wordpress.com 24Quadros: http://24quadros.wordpress.com

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[phoenix] adding const to member_variable bind
by Christian Henning 16 Nov '08

16 Nov '08

Hi there, the following code doesn't compile since I'm iterating over a constant vector of points. struct point { double _prob; double _x; }; void test( const std::vector< point >& d ) { double sum_prob = std::accumulate( d.begin() , d.end() , 0.0 , arg1 + bind( &point::_prob, arg2 ) ); } int _tmain(int argc, _TCHAR* argv[]) { std::vector< point > d; test( d ); return 0; } My question is how can I convert or cast the "&point::_prob" into a const reference? I tried several ways but they all don't work. The only thing that worked was to add const getter function in my point structure. Like this: struct point { point( double prob, double x ) : _prob( prob ), _x( x ) {} const double& prob() const { return _prob; } double _prob; double _x; }; Thanks, Christian

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