November 2002 - Boost-users

Getting a matrix to the -1 power
by agiatojon 14 Nov '02

14 Nov '02

Hello all, I am trying to evaluate a matrix to the -1 power but have not been able to find a quick and dirty solution. Any suggestions? Thanks! Jon Agiato JonAgiato(a)nyc.rr.com

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Preprocessor lib problems on Solaris (Forte compiler)
by Robert A. Reece 14 Nov '02

14 Nov '02

I'm using Forte 6 update 2 to compile my code. The preprocessor headers seem to have problems with all the various macros that get defined. These are the errors I'm seeing from compiling libs/preprocessor/test/list.cpp (using command CC -I../../.. list.cpp): /hades03/pegstage/boost/boost_1_29_0/libs/preprocessor/test> /../.. list.cpp < "list.cpp", line 24: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 24: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 24: Error: BOOST_PP_LIST_FOLD_LEFT_129 is not defined. "list.cpp", line 24: Error: BOOST_PP_NIL is not defined. "list.cpp", line 24: Error: BOOST_PP_TUPLE_EAT_3 is not defined. "list.cpp", line 24: Error: Badly formed expression. "list.cpp", line 25: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 25: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 25: Error: BOOST_PP_LIST_FOLD_LEFT_129 is not defined. "list.cpp", line 25: Error: BOOST_PP_NIL is not defined. "list.cpp", line 25: Error: BOOST_PP_TUPLE_EAT_3 is not defined. "list.cpp", line 25: Error: Badly formed expression. "list.cpp", line 26: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 26: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 26: Error: BOOST_PP_LIST_FOLD_LEFT_129 is not defined. "list.cpp", line 26: Error: BOOST_PP_NIL is not defined. "list.cpp", line 26: Error: BOOST_PP_TUPLE_EAT_3 is not defined. "list.cpp", line 26: Error: Badly formed expression. "list.cpp", line 28: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 28: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 28: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 28: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 28: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 28: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 28: Error: BOOST_PP_LIST_FOLD_LEFT_129 is not defined. "list.cpp", line 28: Error: BOOST_PP_NIL is not defined. "list.cpp", line 28: Error: BOOST_PP_TUPLE_EAT_3 is not defined. "list.cpp", line 28: Error: Badly formed expression. "list.cpp", line 30: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 30: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 30: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 30: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 30: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 30: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 30: Error: BOOST_PP_LIST_FOLD_LEFT_129 is not defined. "list.cpp", line 30: Error: BOOST_PP_NIL is not defined. "list.cpp", line 30: Error: BOOST_PP_TUPLE_EAT_3 is not defined. "list.cpp", line 30: Error: Badly formed expression. "list.cpp", line 31: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 31: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 31: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 31: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 31: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 31: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 31: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 31: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 31: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 31: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 31: Error: BOOST_PP_LIST_FOLD_LEFT_129 is not defined. "list.cpp", line 31: Error: BOOST_PP_NIL is not defined. "list.cpp", line 31: Error: BOOST_PP_TUPLE_EAT_3 is not defined. "list.cpp", line 31: Error: Badly formed expression. "list.cpp", line 33: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 33: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "list.cpp", line 33: Error: BOOST_PP_LIST_FIRST_I is not defined. Compilation aborted, too many Error messages. Any thoughts would be great. -Rob

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RE: [Boost-Users] A strange question-)
by Aleksey Gurtovoy 14 Nov '02

14 Nov '02

Sam Gentile wrote: > I'm sorry, no I still don't understand. Could you please say more? Well, it would help me if you've said what exact points in my answer you are having troubles with :). Aleksey > > -----Original Message----- > From: Aleksey Gurtovoy [mailto:alexy@meta-comm.com] > Sent: Wednesday, November 13, 2002 3:19 AM > To: 'Boost-Users(a)yahoogroups.com' > Subject: RE: [Boost-Users] A strange question-) > > > > Sam Gentile wrote: > > I went there and indeed it can't get any simpler - at least > > in theory-) > > Read the document > > C:\Boost\boost_1_29_0\libs\type_traits\c++_type_traits.htm > > and its quite > > simple: > > > > template <typename T> > > struct is_void > > { static const bool value = false; }; > > > > template <> > > struct is_void<void> > > { static const bool value = true; }; > > > > That's exactly what I want to show. So I go to the header files and > > instead: > > > > //* is a type T void - is_void<T> > > > > BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_void,T,false) > > > > BOOST_TT_AUX_BOOL_TRAIT_SPEC1(is_void,void,true) > > > > > > > > Huh? So I look in bool_trait_def.hpp: > > > > #define BOOST_TT_AUX_BOOL_TRAIT_DEF1(trait,T,C) \ > > > > template< typename T > struct trait \ > > > > : mpl::bool_c< C > \ > > > > { \ > > > > BOOST_TT_AUX_BOOL_TRAIT_VALUE_DECL(C) \ > > > > BOOST_MPL_AUX_LAMBDA_SUPPORT(1,trait,(T)) \ > > > > }; \ > > > Well, the original code doesn't have all these excessive newlines ;), > but > yes, basically that's how it's implemented. > > > Argh! Why is it done like this? This makes it much more > > complicated and unreadable than it has to be. Why are macros > > being used everywhere? > > Practical engineering matters. If you consider that the fact > that there > are > ~60 trait templates in the library and every time when a new > version of > a > compiler comes out, or when somebody starts porting the > library to a new > platform, there is a chance that you need to change half of those > definitions, from, for instance, > > template <typename T> > struct is_void > : mpl::bool_c<false> > { > }; > > to > > template <typename T> > struct is_void > { > BOOST_STATIC_CONSTANT(bool, value = false); > typedef mpl::bool_c<value> type; > }; > > it might all make sense, after all :). Something along the > lines of both > of > the above scenarios has actually happened, a couple of times. It's not > the > whole picture yet, but IMO it's enough of the motivation already, so I > won't > go too deep into details :). > > Hope this answers your question, > Aleksey > > 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] > > > ------------------------ Yahoo! Groups Sponsor > ---------------------~--> > 4 DVDs Free +s&p Join Now > http://us.click.yahoo.com/pt6YBB/NXiEAA/ASSHAA/EbFolB/TM > -------------------------------------------------------------- > -------~-> > > 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/

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RE: [Boost-Users] A strange question-)
by Jim.Hyslop 14 Nov '02

14 Nov '02

Sam Gentile [mailto:ManagedCode@attbi.com] wrote: > Well at least you gave somewhat of an answer. I still want to > understand > how those particular macros give that portability. I haven't looked at the macros in question, but one approach to portability is to separate the macro definitions into platform-specific files. Exactly which file gets included depends on the compiler settings. For example: // file: compilerX/defines.h [omitting include guards for brevity #define DO_SOMETHING(x) CallCompilerXFn( x ) // end file // file: compilerY/defines.h #define DO_SOMETHING(x) compiler_y_function( x ) // end file // file: some Boost header #include "defines.h" class someClass { void f(T a) { DO_SOMETHING( a ); } }; Exactly _which_ "defines.h" gets included is controlled by the build settings, which are determined by the platform. The alternative is a really ugly set of #ifdefs: // file: some Boost header class someClass { void f(T a) { #ifdef COMPILER_X CallCompilerXFn( a ); #elif defined(COMPILER_Y) compiler_y_function( a ); [... etc. for each platform supported #endif } }; As I said, that's _one_ approach - Boost uses something slightly different. Have a look at config.hpp to see its approach. -- Jim

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RE: [Boost-Users] A strange question-)
by Tom Matelich 14 Nov '02

14 Nov '02

Can't say for sure if it'll be helpful, but you might trace the file's evolution using the web interface to cvs on sourceforge. > -----Original Message----- > From: Sam Gentile [mailto:ManagedCode@attbi.com] > Sent: Thursday, November 14, 2002 10:28 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. > > ----------------------------------------------------------------------- DISCLAIMER: Information contained in this message and/or attachment(s) may contain confidential information of Zetec, Inc. If you have received this transmission in error, please notify the sender by return email. -----------------------------------------------------------------------

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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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