- Boost-users - lists.boost.org

RE: [Boost-users] shared_ptr<> w/ Boost::Python
by Nat Goodspeed 30 Oct '04

30 Oct '04

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org [mailto:boost-users- > bounces(a)lists.boost.org] On Behalf Of John Meinel > Sent: Saturday, October 30, 2004 9:24 AM > To: boost-users(a)lists.boost.org > Subject: [Boost-users] shared_ptr<> w/ Boost::Python > > In the boost::python tutorial, they talk about when you return a raw > reference or pointer, you need to wrap it to manage lifetime of the > object. > http://www.boost.org/libs/python/doc/tutorial/doc/call_policies.html > > In the beginning of that page, they talk about how smart pointers are > better for defining the scope and lifetime of objects, but sometimes raw > pointers are necessary. I've gotten pretty good about when to > manage_new_object, or return_internal_reference, etc. > > However, now that I have changed my return functions to actually return > a smart pointer, it doesn't seem like I should need to wrap the return > value anymore. Only now, when I try to do a "get" it gives me the error: > > " No to_python (by-value) converter found for C++ type: class > boost::shared_ptr<class mine> " > > I have a converter for "class mine". I actually thought that the > lifetime managers were using a shared_ptr, so if I did it myself, it > would just be transparent. [Nat] We tell boost::python the smart pointer type we're using, like this: class_<DrawableInterface, DrawablePtr, boost::noncopyable> ("DrawableInterface", no_init) ; where DrawablePtr is a typedef for the smart pointer type.

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uBLAS bindings
by Daniel L Elliott 30 Oct '04

30 Oct '04

Hello, I would like to post this to uBLAS-users, but I am not yet a member. If anyone knows how to fix this, I would appreciate your help. I am working on adding identity matrices (and perhaps some others) to the gesv method of the LAPACK bindings. I have a couple questions about the code. In the template <typename MatrA, typename MatrB, typename IVec> inline int gesv (MatrA& a, IVec& ipiv, MatrB& b) method the static asserts are checking for the matrix types allowed within the gesv type? Instead of using gesv to invert a very large matrix (which would require us to create a very large identity matrix), would it be advisable to simply triangularize matrix A (maybe using LU) and use the uBLAS solver and an identity_matrix? Also, any overview of how the bindings and traits work would be very helpful! Thank you, Dan Elliott

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boost::function
by sboschi75-personal＠yahoo.it 30 Oct '04

30 Oct '04

Hallo, I would like to override operators for boost::function. Forexample I was thinking of an operator "-" : template <T> function<T> operator - (const function<T>& a) { // what do I write here in roder to return the symmetric function? } Thanks Stefano

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i am stuck since a week here: need help:scoping error when trying to make boost work with luabind
by Rohit O chokhani 30 Oct '04

30 Oct '04

Hi, i am a rookie as far as boost is concerned and i am trying to make boost work but just cant...on the point of giving up on it...so please help asap.... i am trying to use a scripting language called lua with my c++ source code. FOr that I felt the need to use luabind library which is completely dependent on boost.(project specific reasons for selecting luabind) As a result i need to have boost on my system. For the past 3-4 days ever since i have been trying to make boost works i have been getting all sorts of compilation errors. mainly they are as follows: C:\Program Files\Microsoft Visual Studio\VC98\INCLUDE\memory(16) : error C2059: syntax error : 'string' C:\Program Files\Microsoft Visual Studio\VC98\INCLUDE\memory(17) : error C2091: function returns function C:\Program Files\Microsoft Visual Studio\VC98\INCLUDE\memory(17) : error C2809: 'operator new' has no formal parameters C:\Program Files\Microsoft Visual Studio\VC98\INCLUDE\memory(20) : error C2954: template definitions cannot nest C:\BOOST2\BOOST\boost/mpl/aux_/integral_wrapper.hpp(88) : fatal error C1506: unrecoverable block scoping error Error executing cl.exe. i did find some solutions of the various forums of boost recommending to build the latest version from cvs in order to get rid of the scoping issue. however, that hasnt solved my case. could anyone kindly suggest some fixes, i would really appreciate it, thanks and regards, rohit __________________________________ Do you Yahoo!? Yahoo! Mail Address AutoComplete - You start. We finish. http://promotions.yahoo.com/new_mail

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RE: [Boost-users] Re: Boost work-in-progress list?
by Brian Braatz 29 Oct '04

29 Oct '04

> bounces(a)lists.boost.org] On Behalf Of Jeff Garland > > On Fri, 29 Oct 2004 11:10:11 -0600, Brian Braatz wrote > > That is an extremely good idea (putting up that Wiki). THANK YOU > > This point was discussed at the Boost/OOPSLA workshop held earlier in the > week. There was general agreement that we need to do a better job of > keeping > this list up to date and helping people find it. I'll be posting more > details > on the workshop results probably sometime next week. > > Jeff > > http://www.crystalclearsoftware.com/cgi- > bin/boost_wiki/wiki.pl?OOPSLA2004/Workshop > [Brian Braatz] Thanks Jeff. I missed the boost workshop as there were 2 tutorials given that my boss insisted I attend which conflicted. I will be very interested to read the notes from that workshop. ( I did stop by around 12:30 for Dave A's talk on Python, but noone was there- must have still been at lunch).. One question- What is the intended usage of the Wiki of things folks are working on for potential boost submission? I ask because I am preparing some info to send out to the list and basically in a spot where I will be one of those folks. (or maybe I should just wait patiently for your notes and all will be revealed ? :) )

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cross compile (ARM target)
by Josiah Bryan 29 Oct '04

29 Oct '04

Greets Boost users - I've just begun to play with boost for usage in a making my own GUI for my PDA (SimPAD), using AGG to render the widgets and Boost for the toolkit-type libraries (in place of the nice-but-GPLed Qt from trolltech). My question for you guys is this: 1) Is it possible to specify an abritray cross compiler for boost? - my build machine: Mandrake Linux 10.0 - cross compiler: gcc version 2.95.2 19991024 (release) - installed in /opt/Embedix/tools/bin/arm-linux-* 2) Is there already a predefined cross-compiler "target" for jam? Or maybe somebody understands what i need to do to get it crosscompiled, and can answer the question even if im not *asking* the right questions. :-) Any help is welcome.. Thanks! -- Josiah Bryan IT Coordinator Productive Concepts, Inc. jbryan(a)productiveconcepts.com (765) 964-6009, ext. 224

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RE: [Boost-users] gcc-3.4.1 and add_const
by Foster, Gareth 29 Oct '04

29 Oct '04

This randomly made me wonder ... if(const int * == int const *) Is that just a personal preference thing? Gaz -----Original Message----- From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Peter Dimov Sent: 26 October 2004 14:21 To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] gcc-3.4.1 and add_const Alexander Neubeck wrote: > Hi. > > I recognized a strange (wrong?) behaviour of gcc-3.4.1 (and > gcc-3.3.3). > When adding const to a type T and this type T is a reference, the > result is just T again (with reference, but witout const)! > Then I tested, if boost handles this case correctly, and it didn't. > The type of add_const< int & >::result is int & and not as expected > const int &. Your expectation was wrong. A "const" reference to int is not the same as a reference to a const int. [...] > My questions to you: > Can anybody verify this behaviour? > Is this behaviour intended? > If yes, WHY? Because that's how top-level const works. int * const != int const *, and int & const != int const &. > P.S: > It was quite difficult to check, which result-type the add_const > really created. First I used typeid( ... ).name(). But then I > recognized that int, int &, const int & produce ALL THE SAME name?!? Yes, that's how typeid works. _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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RE: [Boost-users] Re: Boost work-in-progress list?
by Brian Braatz 29 Oct '04

29 Oct '04

That is an extremely good idea (putting up that Wiki). THANK YOU > -----Original Message----- > From: boost-users-bounces(a)lists.boost.org [mailto:boost-users- > bounces(a)lists.boost.org] On Behalf Of Aleksey Gurtovoy > > "Libraries Under Construction" page on the Boost Wiki > (http://www.crystalclearsoftware.com/cgi- > bin/boost_wiki/wiki.pl?LibrariesUnderConstruction) > is supposed to serve the purpose, but it's not up-to-date at the moment. > > You might consider posting a request for an update on this to the > developers list. > > HTH, > -- > Aleksey Gurtovoy

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RE: [Boost-users] tcp/ip software
by Brian Braatz 29 Oct '04

29 Oct '04

You can also look at ACE http://www.cs.wustl.edu/~schmidt/ACE.html It is very powerful, and quite stable, but it does not use modern C++ techniques. > -----Original Message----- > From: boost-users-bounces(a)lists.boost.org [mailto:boost-users- > bounces(a)lists.boost.org] On Behalf Of Aaron W. LaFramboise > Sent: Monday, October 25, 2004 7:30 PM > To: boost-users(a)lists.boost.org > Cc: 0(a)main.gmane.org > Subject: Re: [Boost-users] tcp/ip software > > Greg Silverman wrote: > > Since Boost does not have a library for TCP/IP, I was wondering what OO > > interface to sockets is most popular with Boost users? > > Giallo <http://giallo.sourceforge.net> is a work-in-progress candidate > for a future Boost sockets library. > > Aaron W. LaFramboise > _______________________________________________

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RE: [Boost-users] uBLAS past, present, and future.
by Foster, Gareth 29 Oct '04

29 Oct '04

Doesn't freshmeat/sourceforge give you that automatically somehow? I remember seeing some sort of league table of the most 'active' projects on one of the two sites, taking that figure is something that could be automated, and so wouldn't go out of date, it might be a good start? If the code isn't on freshmeat/sourceforge maybe the same thing could be setup on the server where boost source is stored? Thinking about it, you could probably list the number of hackers on each project too, that would be a useful statistic. And what about bugs? Maybe the number of bugs in the bugzilla database (if there is one) could be shown too, that would go some way to indicating stability. And if there is an issuezilla (like openoffice.org has) then that might say something about completeness? The severity rating of each bug would be useful too ... Using all this stuff in a clever way, you could really come up with a groovy stats page for each project perhaps. Hope these ideas are helpful! Gaz -----Original Message----- From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Aaron W. LaFramboise Sent: 28 October 2004 20:25 To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] uBLAS past, present, and future. Daniel L Elliott wrote: > I am trying to better understand the current status of the uBLAS library. > Below I have listed a few questions. Of course, any responses are > completely off the record. We just need to get a better idea of the > current state of uBLAS. Thank you, in advance, for any information you > provide. I don't have the answers to these questions, but to be honest, I wish that every library in Boost had answers to all of these questions up in front on the main page of their documentation. These are very important peices of information, and misunderstandings with regards to these issues in general has created a lot of problems in the past. Sometimes, it would just be nice to have an honest indication of project vitality. Aaron W. LaFramboise _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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