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RE: [Boost-users] Intoductory Boost Presentation
by Darryl Green 11 Nov '03

11 Nov '03

Hi Jon, > -----Original Message----- > From: Jon Kalb [mailto:Kalb@LibertySoft.com] > Sent: Tuesday, 11 November 2003 11:16 AM > To: Boost Users > Subject: Re: [Boost-users] Intoductory Boost Presentation > > > On 11/9/03 8:06 PM, "Matthew S Trentini" <matt_s_trentini(a)hotmail.com> > wrote: > > > Heya Everyone, > > > > I recently gave a presentation to my work colleagues on the > wonders of the > > Boost library. [snip] > > Matt, > > I don't know if you plan to keep this updated, but here is > some feedback > from a co-worker. I have not verified his findings. > [snip] > > > > The rest of the pages have the classic boost downfall: they > > don't discuss any of the pitfalls, performance problems, or > > code bloat issues, which frankly, seem like the "crazy aunt > > in the basement" of boost. > I don't suppose your co-worker would like to enlighten us about these issues/areas with which he obviously has some expertise and considers the documentation (and the code?) deficient? That would be as useful as Matt's overview could be to those just getting into/considering using boost libs. As it stands, all that the above statement adds is FUD. Regards Darryl Green ########################################################################## This e-mail is for the use of the intended recipient(s) only. If you have received this e-mail in error, please notify the sender immediately and then delete it. If you are not the intended recipient, you must not use, disclose or distribute this e-mail without the author's prior permission. We have taken precautions to minimise the risk of transmitting software viruses, but we advise you to carry out your own virus checks on any attachment to this message. We cannot accept liability for any loss or damage caused by software viruses. ##########################################################################

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Library array
by Dave 11 Nov '03

11 Nov '03

Hello all, I have recently reviewed the Boost presentation put together by Matthew and intend to present it to my peers also. It was especially welcome to see this because I've been wanting to present to my peers on Boost for awhile but haven't had the time to learn enough about the library to put a presentation together. So, something I wanted fell right in my lap! Kinda like finding a $100 bill on the street! I do have one question about the array library. In the documentation, the statement is made that the advantage array has over vector is the fact that since vectors provide the semantics of dynamic arrays, "This results in some overhead in case only arrays with static sizes are needed.". When discussing this with my peers, I'd like to present something a little more concrete to them. If I have a number of elements that is known at compile time, why, *specifically*, should I prefer boost::array to std::vector? Thanks! Dave

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problem with versio 1_30_0
by S.M. Sohelozzaman 11 Nov '03

11 Nov '03

Hello all, I am a new member of this group and I am facing some problems with the new boost version. I was trying to compile and link my old C++ codes with the new boost version (1_30_0 and 1_30_2). It compiles but during the linking time it gives the following errors: ======================================================= Boost Root = /home/sohel/projects/boost_1_30_0 Applications lib: /home/sohel/projects/boost_1_30_0/libs/thread/build/bin/libboost_thread.so/gcc/debug/runtime-link-dynamic/shared-linkable-true/threading-multi/libboost_threadd.so NT: boost: 30 ...patience... don't know how to make /home/sohel/projects/boost_1_30_0/libs/thread/build/bin/libboost_thread.so/gcc/debug/runtime-link-dynamic/shared-linkable-true/threading-multi/libboost_threadd.a ...found 390 targets... ...can't find 1 target... ...can't make 7 targets... ...skipped 000_easy_positioning for lack of /home/sohel/projects/boost_1_30_0/libs/thread/build/bin/libboost_thread.so/gcc/debug/runtime-link-dynamic/shared-linkable-true/threading-multi/libboost_threadd.a... ======================================================= Please help me with the ideas how I can solve this problem. Thanks in advance. Sohel. __________________________________ Do you Yahoo!? Protect your identity with Yahoo! Mail AddressGuard http://antispam.yahoo.com/whatsnewfree

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Re: [Boost-users] Re: Note for Python 2.3 users
by Paul Grenyer 11 Nov '03

11 Nov '03

> "Paul Grenyer" <paul(a)paulgrenyer.co.uk> writes: Hi > > I assume this means I need to use Python 2.2.3 or lower, right? > > I recommend posting Boost.Python questions to the C++-sig: > http://www.boost.org/more/mailing_lists.htm#cplussig Thanks, I've joined. > and I also recommend using the CVS version of Boost.Python, which is > Python-2.3 compatible. Thanks, getting it now. Regards Paul Please note the change of email address! Paul Grenyer Email: paul(a)paulgrenyer.co.uk Web: www.paulgrenyer.co.uk

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RE: [Boost-users] Library array
by Ben Hutchings 11 Nov '03

11 Nov '03

Dave <better_cs_now(a)yahoo.com> wrote: <snip> > I do have one question about the array library. In the > documentation, the statement is made that the advantage array has > over vector is the fact that since vectors provide the semantics > of dynamic arrays, "This results in some overhead in case only > arrays with static sizes are needed.". When discussing this with > my peers, I'd like to present something a little more concrete to > them. > > If I have a number of elements that is known at compile time, why, > *specifically*, should I prefer boost::array to std::vector? The array is stored inside the class instance rather than separately allocated from the heap. There is no need for additional pointer and size member data. This saves time and memory. Many member functions are trivial because of the fixed size. This also saves time. The array size is exactly what you specify, whereas std::vector may round up the size of its internal array to allow for some growth. This saves memory. There may also be a reduction in mental overhead because you will never have to think about the possibility of the array size changing. One disadvantage is that you can catch a failed heap allocation whereas a failed automatic allocation is normally fatal. Allocating large arrays in automatic storage remains a bad idea. Ben.

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RE: [Boost-users] date_time: why invalid_time_label in process_local_dst_start_day()
by Ben Hutchings 11 Nov '03

11 Nov '03

Michael Haubenwallner <michael.haubenwallner(a)salomon.at>: > as i could not google out an answer for my problem with > boost/date_time/dst_rules.hpp: is there a reason why > "boost::date_time::dst_calculator::process_local_dst_start_day()" > returns "invalid_time_label" for the transition time, but > "process_local_dst_end_day()" returns "ambigous" ? > Or is it just a bug ? At the start of DST, the time goes directly from, say, 1:00 to 2:00, so there is *no* point in time labelled 1:30 and it is invalid. At the end of DST, the time goes directly from, say, 2:00 to 1:00, so there are two points in time labelled 1:30 and it is ambiguous.

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date_time: why invalid_time_label in process_local_dst_start_day()
by Michael Haubenwallner 11 Nov '03

11 Nov '03

Hello, as i could not google out an answer for my problem with boost/date_time/dst_rules.hpp: is there a reason why "boost::date_time::dst_calculator::process_local_dst_start_day()" returns "invalid_time_label" for the transition time, but "process_local_dst_end_day()" returns "ambigous" ? Or is it just a bug ? Thanks, Michael Haubenwallner -- Michael Haubenwallner SALOMON Automation GmbH Forschung & Entwicklung A-8114 Friesach bei Graz mailto:michael.haubenwallner@salomon.at http://www.salomon.at

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Boost Python: Beyond handles
by Paul Grenyer 11 Nov '03

11 Nov '03

Hi All I'm trying to embed the python interpreter in a C++ program so that users can write simple scripts that can be executed when the program runs. I've been following the "Using the the Interpretter" examples an dhave had quite a lot of success, except with this one: handle<> main_module(borrowed( PyImport_AddModule("__main__") )); handle<> main_namespace(borrowed( PyModule_GetDict(main_module.get ()) )); handle<> main_module( borrowed( PyImport_AddModule("__main__") )); main_namespace dict(handle<>(borrowed( PyModule_GetDict(main_module.get ()) ))); handle<>( PyRun_String(" result = 5 ** 2", Py_file_input, main_namespace.ptr(), main_namespace.ptr()) ); int five_squared = extract<int>( main_namespace["result"] ); I'm using boost 1.30.0 and MSVC 7.1, along with the following warning (?!!): builtin_converters.hpp(114) : warning C4267: 'argument' : conversion from 'size_t' to 'int', possible loss of data I get the following errors: error C2146: syntax error : missing ';' before identifier 'dict' error C2039: 'ptr' : is not a member of 'boost::python::handle<>' error C2039: 'ptr' : is not a member of 'boost::python::handle<>' error C2676: binary '[' : 'boost::python::handle<>' does not define this operator or a conversion to a type acceptable to the predefined operator The "missing ';' before identifier 'dict'" error I can understand and I ppear to be able to fix by swapping "main_namespace" for "handle<>". I can also fix the "'ptr' : is not a member of 'boost::python::handle<>'" error by changing ptr to get. However, the final error has me stumped. Any suggestions appreciated. Regards Paul Please note the change of email address! Paul Grenyer Email: paul(a)paulgrenyer.co.uk Web: www.paulgrenyer.co.uk

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Note for Python 2.3 users
by Paul Grenyer 11 Nov '03

11 Nov '03

Hi All I'm just about to start trying to use Boost.Python for the first time and noticed the following note in the docs: Note for Python 2.3 users This is a bugfix release only, and is not compatible with Python 2.3. Boost 1.31.0, which will be compatible with Python 2.3, is due out shortly. I assume this means I need to use Python 2.2.3 or lower, right? Regards Paul Please note the change of email address! Paul Grenyer Email: paul(a)paulgrenyer.co.uk Web: www.paulgrenyer.co.uk

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'long long' problem on VC++7.1
by Nick Savoiu 11 Nov '03

11 Nov '03

I'm trying to compile some boost code on VC+7.1 but I get: e:\users\savoiu\Projects\boost-1.30.2\boost\concept_check.hpp(183) : error C2632: 'long' followed by 'long' is illegal Do I need any #defines when using Boost with VC++7.1 or should it work right out of the box? Thanks, Nick

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