October 2008 - Boost - lists.preview.boost.org

daylight save for time zone on trac
by Peng Yu 21 Oct '08

21 Oct '08

Hi, https://svn.boost.org/trac/boost/prefs/datetime There is no such option for daylight saving. Can somebody add that option? Thanks, Peng

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[serialization] basic_xml_grammar.hpp broken
by Eric Niebler 21 Oct '08

21 Oct '08

Changeset 49349 broke the xml archive, and wave with it. http://svn.boost.org/trac/boost/changeset/49349/trunk/boost/archive/impl/ba… // spirit stuff #if (defined __BORLANDC__) && (__BORLANDC__ < 0x593) \ || (defined _MSC_VER) && #if (_MSC_VER <= 1300) Whoops-------------------^^^ -- Eric Niebler BoostPro Computing http://www.boostpro.com

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[ublas] slice iterators are indexed iterators
by Neal Becker 21 Oct '08

21 Oct '08

It seems that basic_slice iterators are indexed, they store an integral index and dereference looks like: return (*this) ().start () + it_* (*this) ().stride (); This seems to kill performance. Is there any good reason why slice iterators could not be based on pointers? If it were, the most common use, which would iterate using 'it++' should be faster.

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The status of Proto
by Peng Yu 21 Oct '08

21 Oct '08

Hi, It is exciting to know Proto helps the development of expression template based library. Since learning it and use it efficiently could take quite a lot of time, I want to know whether it is almost stable right now. Or it will subject to some further changes in the future. Does it have any limit on what kinds of expression template based designs it can be used? If Proto is good enough, can it be used to reimplement many expression template based pacakges, boost.ublas, blitz++, etc.? Thanks, Peng

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[date_time] Time zone improvements
by Rutger ter Borg 21 Oct '08

21 Oct '08

Dear Boost.Date_Time developers, Being a heavy user of Boost's Date_Time library, I think it is very useful. However, I think one area could use improvement: its time zone handling. I would like to bring the full Olson tz database [1] to Boost.Date_Time. This offers a very high-quality, and, on package-managed-UNIX-systems, a maintainance-free solution to a time zone database. I have written a modern C++ implementation for reading zic-compiled binary zoneinfo-files. At the moment, Boost.Date_Time is not able to represent time zones that have DST offsets and/or zone abbreviations depending on (or, changing over) time. I.e., if a country or locality changes its time zone definitions. E.g., a system that is in "Europe/Amsterdam" has changing DST offset and time zone abbreviation, which depend on time $ date -d "2008-10-10 20:00:00Z" Fri Oct 10 22:00:00 CEST 2008 $ date -d "1930-10-10 20:00:00Z" Fri Oct 10 20:19:32 AMT 1930 I would like to propose changes that enables Boost.Date_Time to represent time zone definitions that change over time. The semantics will remain similar to the current version, boost::shared_ptr< time_zone > my_zone( "Europe/Amsterdam" ); local_date_time some_time( pt, my_zone ); some_time.utc_time(); // 2008-Oct-10 20:00:00 some_time.local_time(); // 2008-Oct-10 22:00:00 some_time.is_dst(); // true some_time.zone_abbrev(); // "CEST" some_time.dst_offset(); // 02:00:00 in addition, the abstract Time Zone interface and supported accessors will have to undergo a change. Although the desired result may be achieved in multiple ways, I think the time zone base could support accessors like from_utc( ptime const& p) and from_local(...) methods, perhaps returning a (pointer to a) ttinfo tuple, // UTC offset, is_dst, abbreviation typedef boost::tuple< time_duration_type, bool_type, string_type > ttinfo; and/or a special type in case the conversion is ambigious. When using the Olsen data base, this structure could be looked up through from_utc using std::lower_bound on a std::map or a ptr_map of transition points. I see a local_time_iterator is absent from the library, which I would like to add as well. By way of this email I would like to ask whether there is interest the proposed improvement. If so, please let me know, so we can work on the details. Kind regards, Rutger ter Borg [1] Sources for Time Zone and Daylight Saving Time Data, http://www.twinsun.com/tz/tz-link.htm

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Re: [boost] [1.37.0][serialization] Assertion failed at libs/serialization/src/extended_type_info.cpp:92
by Hartmut Kaiser 21 Oct '08

21 Oct '08

> Anything I can do about this? > What does this assertion mean? > > My setup: Linux 64Bit, gcc 4.2.4, serialization is used for polymorphic > objects loaded from different shared libraries, shared libraries are > loaded with dlopen(RTLD_GLOBAL|RTLD_LAZY). > > Assertion (extended_type_info.cpp:92) occurs during program termination > (after main returned), during dlclose(). > > If anything else isn't possible, would it be appropriate to change the > related code (before the release!) from: > > assert(start != end); > > // remove entry in map which corresponds to this type > do{ > if(this == *start) > x.erase(start++); > else > ++start; > }while(start != end); After looking at this code again I have the impression that it is broken anyways. You can't safely increment an iterator after deleting the object it points to: erase(start++). This code relies on the fact that in order to be incremented the iterator doesn't need the object it points to (which at least for lists is a wrong assumption). Regards Hartmut > > To: > > assert(start != end); > > // remove entry in map which corresponds to this type > while(start != end) { > if(this == *start) > x.erase(start++); > else > ++start; > } > > Which wouldn't remove the problem, but at least avoids hanging the > program if assertions are off... > > Regards Hartmut

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Selective Unit Testing
by dominic ibeme 21 Oct '08

21 Oct '08

Hi .. I've been using the boost unit testing framework and its quite a wonderful library... thanks to Gennadiy, however the section on advanced usage wasn't made available in release 1.36. i would really like to know how to perform selective testing i.e executing test with dependencies, i guess this would show up in the future, but i kind of need help on this one. This request list has been extremely helpful..

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[mp_int] new release
by Kevin Sopp 21 Oct '08

21 Oct '08

Hi all, I made a new release of my multiprecision integer library with the following changes: - improved documentation - serialization support - bugfixes - improved benchmark tool - prime generation has been reworked - probably some other things which I forgot I believe it's pretty much ready for review now. The mp_int reference section is slightly lacking in a few places, but other than that I think it's pretty solid. I have a few things in mind for the future of this library: - improved division and squaring algorithms according to the papers on my disk. - an implementation of an mp_int proxy type that acts on preallocated memory, but does not manage memory itself. This can then be used to improve the runtime of several algorithms. - expression template support There is pregenerated html documentation under libs/mp_math/doc/html/ http://www.boostpro.com/vault/index.php?action=downloadfile&filename=mp_mat… Kevin Sopp

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[doc]Traduction of the documentation
by Alp Mestan 21 Oct '08

21 Oct '08

Hi, The French most active and visited developer community, Developpez.com, would like to know if you were okay to do the traduction of Boost's doc, because it's a problem for many of our visitors that the doc is only readable in English. Would you be okay ? Best regards. -- Alp Mestan --- http://blog.mestan.fr/ --- http://alp.developpez.com/ --- In charge of the Qt, Algorithms and Artificial Intelligence sections on Developpez

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[1.37.0] pre-beta snapshot available
by Beman Dawes 21 Oct '08

21 Oct '08

The boost-posix and boost-windows snapshots of what will become the 1.37.0 beta are available. See http://boost.cowic.de/rc/ It would be helpful to get confirmation that these look OK. Past snapshots, betas, and release had been built on a Windows system, but 1.37.0 is being built on a Linux system to try to avoid doc build problems that plague the Windows variant. As always, separate svn exports are done, requesting the appropriate line endings, but I'd still like more eyeballs on this to make sure all is well. I'd specifically like confirmation from Eric and Daniel that the built docs look OK. If all is well, I'll build the beta tomorrow. In the meantime, no branches/release commits, please. Thanks, --Beman

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