- Boost-users - lists.boost.org

RE: [Boost-Users] A strange question-)
by Garriss, Michael 14 Nov '02

14 Nov '02

No problem. We all know how frustrating C++ can be sometimes :) . You're right, what they have done is astounding! -Mike -----Original Message----- From: Sam Gentile [mailto:ManagedCode@attbi.com] Sent: Thursday, November 14, 2002 11:28 AM To: Boost-Users(a)yahoogroups.com Subject: RE: [Boost-Users] A strange question-) You're right of course. I do realize that everyone works on this in their "free time," and what has been accomplished has been astounding to say the least. I'm sorry for my rant and I'll re-look at his reply and try to figure it out. Once again, I apologize. Sam Gentile .NET Consultant ManagedCode(a)nospam.attbi.com http://www.samgentile.com http://radio.weblogs.com/0105852/ -----Original Message----- From: Garriss, Michael [mailto:michael.garriss@abacus-direct.com] Sent: Thursday, November 14, 2002 12:57 PM To: 'Boost-Users(a)yahoogroups.com' Subject: RE: [Boost-Users] A strange question-) Keep in mind that Aleksey doesn't get paid for this and he answered your mail on his "free" time. Cut him some slack! I thought his answers for well written. -Mike Garriss -----Original Message----- From: Sam Gentile [mailto:ManagedCode@attbi.com] Sent: Thursday, November 14, 2002 9:29 AM To: Boost-Users(a)yahoogroups.com Subject: RE: [Boost-Users] A strange question-) Well at least you gave somewhat of an answer. I still want to understand how those particular macros give that portability. Sam Gentile .NET Consultant ManagedCode(a)nospam.attbi.com http://www.samgentile.com http://radio.weblogs.com/0105852/ -----Original Message----- From: Jeff Garland [mailto:jeff@crystalclearsoftware.com] Sent: Thursday, November 14, 2002 11:13 AM To: Boost-Users(a)yahoogroups.com Subject: RE: [Boost-Users] A strange question-) > <rant> > > How positively delightful to wait 24 hours and get a non-response like > this. This is like pulling blood out of a stone. At this point, I'll Sorry for your frustrations, but imagine the frustration of the library author after yet another bizarre compiler error on perfectly standard C++. Anyway, I think the answer was in the previous mail: Portability. In an ideal world most of this sort of macro hackery wouldn't exist. Unfortunately, boost exists in the real world... > just forget it and use something else. I do understand that Boost users > tend to be extremely advanced C++ users. For the record, I have been > programming in C++ for well over 10 years and still get confused at > some of the things you do. I am questioning and not understanding your > approach at all. Why? Well, lets look at Stroustrup, 3rd edition page > 160 "Macros are important in C, but have far fewer uses in C++. The > first rule about macros is: Don't use them if you don't have to. Almost > every macro demonstrates a flaw in the program, or the programmer." > Then "avoid macros." Now, I'm sure I'm missing your good reason but there you > go. To me, macros are an ugly legacy from C and render C++ code > unreadable and maintainable. So, how detailed does my question have to > be? I don't understand the whole approach and why it was taken. Is that > clear enough? This viewpoint is just fine if you are creating a library for one platform and compiler. The reality of the current world is that many supposedly standard features of C++ or parts of the standard library are not correct on many of the most common compilers. As a result, if you write a library 'to the standard' it might not get used much since it won't compile or work correctly for most people. In addition, many boost libraries push compilers to the limits and thus for some boost libraries the situation is even more severe. The result is that many boost libraries use various macro techniques to create portable code. Looking ahead a few years most of this will hopefully disappear. HTH, Jeff Info: <http://www.boost.org> Wiki: <http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl> Unsubscribe: <mailto:boost-users-unsubscribe@yahoogroups.com> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ Info: <http://www.boost.org> Wiki: <http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl> Unsubscribe: <mailto:boost-users-unsubscribe@yahoogroups.com> Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. Info: <http://www.boost.org> Wiki: <http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl> Unsubscribe: <mailto:boost-users-unsubscribe@yahoogroups.com> Your use of Yahoo! Groups is subject to the Yahoo! <http://docs.yahoo.com/info/terms/> Terms of Service. [Non-text portions of this message have been removed] Info: <http://www.boost.org> Wiki: <http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl> Unsubscribe: <mailto:boost-users-unsubscribe@yahoogroups.com> Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.

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RE: [Boost-Users] A strange question-)
by Garriss, Michael 14 Nov '02

14 Nov '02

Keep in mind that Aleksey doesn't get paid for this and he answered your mail on his "free" time. Cut him some slack! I thought his answers for well written. -Mike Garriss -----Original Message----- From: Sam Gentile [mailto:ManagedCode@attbi.com] Sent: Thursday, November 14, 2002 9:29 AM To: Boost-Users(a)yahoogroups.com Subject: RE: [Boost-Users] A strange question-) Well at least you gave somewhat of an answer. I still want to understand how those particular macros give that portability. Sam Gentile .NET Consultant ManagedCode(a)nospam.attbi.com http://www.samgentile.com http://radio.weblogs.com/0105852/ -----Original Message----- From: Jeff Garland [mailto:jeff@crystalclearsoftware.com] Sent: Thursday, November 14, 2002 11:13 AM To: Boost-Users(a)yahoogroups.com Subject: RE: [Boost-Users] A strange question-) > <rant> > > How positively delightful to wait 24 hours and get a non-response like > this. This is like pulling blood out of a stone. At this point, I'll Sorry for your frustrations, but imagine the frustration of the library author after yet another bizarre compiler error on perfectly standard C++. Anyway, I think the answer was in the previous mail: Portability. In an ideal world most of this sort of macro hackery wouldn't exist. Unfortunately, boost exists in the real world... > just forget it and use something else. I do understand that Boost users > tend to be extremely advanced C++ users. For the record, I have been > programming in C++ for well over 10 years and still get confused at > some of the things you do. I am questioning and not understanding your > approach at all. Why? Well, lets look at Stroustrup, 3rd edition page > 160 "Macros are important in C, but have far fewer uses in C++. The > first rule about macros is: Don't use them if you don't have to. Almost > every macro demonstrates a flaw in the program, or the programmer." > Then "avoid macros." Now, I'm sure I'm missing your good reason but there you > go. To me, macros are an ugly legacy from C and render C++ code > unreadable and maintainable. So, how detailed does my question have to > be? I don't understand the whole approach and why it was taken. Is that > clear enough? This viewpoint is just fine if you are creating a library for one platform and compiler. The reality of the current world is that many supposedly standard features of C++ or parts of the standard library are not correct on many of the most common compilers. As a result, if you write a library 'to the standard' it might not get used much since it won't compile or work correctly for most people. In addition, many boost libraries push compilers to the limits and thus for some boost libraries the situation is even more severe. The result is that many boost libraries use various macro techniques to create portable code. Looking ahead a few years most of this will hopefully disappear. HTH, Jeff Info: <http://www.boost.org> Wiki: <http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl> Unsubscribe: <mailto:boost-users-unsubscribe@yahoogroups.com> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ Info: <http://www.boost.org> Wiki: <http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl> Unsubscribe: <mailto:boost-users-unsubscribe@yahoogroups.com> Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.

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max, min, VC++6 and 7
by soulofsealion 14 Nov '02

14 Nov '02

Could someone provide me a brief explanation as to why max and min are redefined in \boost\config\suffix.hpp and \boost\config\platform\win32.hpp. It appears that the reason is that the max and min macros defined in windef.h are not type safe. Also, in user application code, would it be recommended to always use the _MAX and _MIN macros in VC++ 6 and 7 so that the STL implementations are always used, and just reserve explicit max and min for the Boost library code?

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Re: Is MTL alive?
by Paul C. Leopardi 14 Nov '02

14 Nov '02

Alexei, See this thread on the MTL-devel mailing list archive: http://www.osl.iu.edu/MailArchives/mtl-devel/msg00435.php As you can see from the mailing list and the download area, there has not been much developer activity since September. There is also an MTL 3 prototype called MXTL at: http://www.mpi.nd.edu/~jsiek/mxtl.html See http://www.osl.iu.edu/MailArchives/mtl-devel/msg00373.php and http://lists.boost.org/MailArchives/boost/msg10435.php Best regards

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Help with boost::function and boost::bind
by electricsnark 14 Nov '02

14 Nov '02

I need to make a registry of callback functions, which are in the form of member functions of objects of various types. ----------- code snippet ----------- class T1 { public: void CallBackFcn(); }; ... class Registry { public: template <typename T> void registerFcn (void (T::*updFcn)(), T* obj ); private: vector< boost::function<void>* > fcnvec; }; template <typename T> void Registry::registerFcn(void (T::*updFcn)(), T* obj) { boost::function<void> *fp = new boost::function<void> ( boost::bind(updFcn,obj) ); fcnvec.push_back( fp ); } main() { .... T1 *pt = new T1; p_Registry->registerFcn(&T1::CallBackFcn, pt); } ----------------------------------------------------- However, before adding the boost::function to the vector, I want to make sure that the callback function isn't already in there. Unfortunately, I can't just look at value of the pointer fp - I need to get to the address of the actual callback function that is to be executed. But I can't figure out how to get there. Any help appreciated.

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Getting a matrix to the power of n
by agiatojon 14 Nov '02

14 Nov '02

Hello all, I am working with a formula which requires me to get the result of a matrix to the power of n (i.e. pow(matrix, n)) but as expected, the <cmath> function pow() is unable to convert from type double to matrix. Does the matrix library have this sort of functionality built in, or maybe some other part of boost? Thanks! Jon Agiato JonAgiato(a)nyc.rr.com

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Problem with matrix_expressions
by agiatojon 14 Nov '02

14 Nov '02

Hello all, I am trying to compile the following code snippet from the documentation of matrix_expressions in which two matrices are used to display the use of addition and subtraction operations. I am not really sure how to post the error messages as there are literally hundreds of them, so here is the code as I am am pretty sure this is going to be one of those well known bugs kind of things. Compiled using VS.NET, debug mode. #include <iostream> #include <boost/numeric/ublas/matrix_expression.hpp> int main() { using namespace boost::numeric::ublas; matrix<double> m1(3, 3), m2(3, 3); for(int i = 0; i < std::min(m1.size1(), m2.size1()); ++i) for(int j = 0; j < std::min(m1.size2(), m2.size2()); ++j) m1(i, j) = m2(i, j) = 3 * i + j; std::cout << m1 + m2 << std::endl; std::cout << m1 - m2 << std::endl; std::cin.get(); return EXIT_SUCCESS; } Thanks! Jon Agiato JonAgiato(a)nyc.rr.com

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ublas/config.hpp compliation error
by Michael Pagels 14 Nov '02

14 Nov '02

This is my first attempt at using ublas, here's the problem -- g++ -DHAVE_CONFIG_H -I. -I.. -I../sg -I../shared -I../include -O2 -g -c Linearity.C -o Linearity.o In file included from ../include/boost/numeric/ublas/matrix.hpp:20, from Linearity.C:16: ../include/boost/numeric/ublas/config.hpp:375: parse error before `,' token ../include/boost/numeric/ublas/config.hpp:381: parse error before `,' token ../include/boost/numeric/ublas/config.hpp:387: parse error before `,' token ../include/boost/numeric/ublas/config.hpp:401: too many template parameter lists in declaration of `typename V::size_type boost::numeric::ublas::num_elements(const V&)' ../include/boost/numeric/ublas/config.hpp:401: syntax error before `{' token ../include/boost/numeric/ublas/config.hpp:404: parse error before `>' token ../include/boost/numeric/ublas/config.hpp:408: parse error before `>' token ../include/boost/numeric/ublas/config.hpp:413: too many template parameter lists in declaration of `typename MV::size_type num_non_zeros(const MV&)' ../include/boost/numeric/ublas/config.hpp:413: syntax error before `{' token /usr/include/g++-v3/bits/std_cmath.h:69: confused by earlier errors, bailing out I'm using boost_1_29_0, and gcc 3.0.4 under Linux. I reviewed the newsgroup and didn't see this problem mentioned, so I'm sure it's something obvious to the experienced. Thanks

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addendum to previous post on matrix_expression
by agiatojon 14 Nov '02

14 Nov '02

Ok, I fixed some of my mistakes but it now appears the overloaded operators aren't being seen so I must be missing another header or something. Once again here's the code compiled under VS.NET, debug, boost version 1_29_0, with the resultant error messages following. #include <iostream> #include <boost/numeric/ublas/matrix.hpp> #include <boost/numeric/ublas/matrix_expression.hpp> int main() { using namespace boost::numeric::ublas; matrix<double> m1(3, 3), m2(3, 3); for(unsigned int i = 0; i < std::min(m1.size1(), m2.size1()); ++i) for(unsigned int j = 0; j < std::min(m1.size2(), m2.size2()); ++j) m1(i, j) = m2(i, j) = 3 * i + j; std::cout << m1 + m2 << std::endl; std::cout << m1 - m2 << std::endl; std::cin.get(); return EXIT_SUCCESS; } c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\test5\matrixAddSub.cpp(15): error C2679: binary '<<' : no operator found which takes a right-hand operand of type 'boost::numeric::ublas::matrix_binary_traits<E1,E2,F>::result_ty pe' (or there is no acceptable conversion) with [ E1=boost::numeric::ublas::matrix<double,boost::numeric::ublas::row_ma jor,boost::numeric::ublas::unbounded_array<double>>, E2=boost::numeric::ublas::matrix<double,boost::numeric::ublas::row_ma jor,boost::numeric::ublas::unbounded_array<double>>, F=boost::numeric::ublas::scalar_plus<boost::numeric::ublas::matrix<do uble,boost::numeric::ublas::row_major,boost::numeric::ublas::unbounde d_array<double>>::value_type,boost::numeric::ublas::matrix<double,boo st::numeric::ublas::row_major,boost::numeric::ublas::unbounded_array< double>>::value_type> ] c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\test5\matrixAddSub.cpp(17): error C2679: binary '<<' : no operator found which takes a right-hand operand of type 'boost::numeric::ublas::matrix_binary_traits<E1,E2,F>::result_ty pe' (or there is no acceptable conversion) with [ E1=boost::numeric::ublas::matrix<double,boost::numeric::ublas::row_ma jor,boost::numeric::ublas::unbounded_array<double>>, E2=boost::numeric::ublas::matrix<double,boost::numeric::ublas::row_ma jor,boost::numeric::ublas::unbounded_array<double>>, F=boost::numeric::ublas::scalar_minus<boost::numeric::ublas::matrix<d ouble,boost::numeric::ublas::row_major,boost::numeric::ublas::unbound ed_array<double>>::value_type,boost::numeric::ublas::matrix<double,bo ost::numeric::ublas::row_major,boost::numeric::ublas::unbounded_array <double>>::value_type> ] Thanks to all for their help! Jon Agiato JonAgiato(a)nyc.rr.com

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[BGL] adjacency_matrix BUG
by mycia 14 Nov '02

14 Nov '02

Hi I compiled the adjacency matrix example in libs/graph/example/adjacency_matrix.cpp however, the output is totally different than expected http://www.boost.org/libs/graph/doc/adjacency_matrix.html it seems that something wrong in out_edges() have any idea? thanks a lot hcyeh

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