- Boost-users - lists.boost.org

using transform_iterator with std::lower_bound
by Alexis H. Rivera-Rios 05 Feb '08

05 Feb '08

Hi, I'm trying to use a transform iterator and lower_bound to search a list of integers as if it was list of booleans. According to the message the const_mem_fun_ref_t doesn't have a default constructor. Is there a way to make this code compile? Your help will be appreciated! Alex #include<functional> #include <vector> #include <algorithm> #include <boost/iterator/transform_iterator.hpp> class T { public: int _a; T(int a) : _a(a) {} bool greaterZero() const { return _a > 0; } }; int main(void) { typedef std::vector<T> Tlist; typedef std::const_mem_fun_ref_t<bool,T> Function; typedef boost::transform_iterator<Function, Tlist::const_iterator> Iterator; Tlist x; Iterator b(x.begin(),std::mem_fun_ref<bool,T>(&T::greaterZero)), e(x.end(),std::mem_fun_ref<bool,T>(&T::greaterZero)); std::lower_bound(b,e,false); } Error log: BD Software STL Message Decryptor v3.10 for gcc 2/3/4 matob.cpp:28:2: warning: no newline at end of file /cygdrive/c/opt/boost_1_34_1/boost/iterator/transform_iterator.hpp: In constructor `boost::transform_iterator< main()::Function, vector<T>::const_iterator, boost::use_default , boost::use_default >::transform_iterator()': stl_algo.h:2627: instantiated from `boost::transform_iterator< main()::Function, vector<T>::const_iterator, boost::use_default , boost::use_default > lower_bound( boost::transform_iterator< main()::Function, vector<T>::const_iterator, boost::use_default , boost::use_default >, boost::transform_iterator< main()::Function, vector<T>::const_iterator, boost::use_default , boost::use_default >, const bool & )' matob.cpp:26: instantiated from here /cygdrive/c/opt/boost_1_34_1/boost/iterator/transform_iterator.hpp:100: error: No match for `const_mem_fun_ref_t<bool, T>::const_mem_fun_ref_t()' stl_function.h:640: candidates are: const_mem_fun_ref_t<bool, T> ::const_mem_fun_ref_t(const const_mem_fun_ref_t<bool, T> &) stl_function.h:644: const_mem_fun_ref_t< bool, T>::const_mem_fun_ref_t(bool (T::*)() const) Programming Tutorial: In Python: To do this, do this In Perl: To do this, do this or this or this or this... In C: To do this, do this, but be careful In C++: To do this, do this, but don't do this, be careful of this, watch out for this, and whatever you do, don't do this ____________________________________________________________________________________ Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs

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timer question...
by Raveendra Madala 05 Feb '08

05 Feb '08

Hi We can use the SetTimer/KillTimer APIs in windows to register a CALLBACK function to handle WM_TIMER messages at (approx) regular intervals of time (or handle WM_TIMER messages in WindowProc). Is there a portable equivalent in boost (thread) library? Boost::timer helps in measurement of time only!! Warm Regards Raveendra

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BoostCon - Call for Sessions
by Jeff Garland 05 Feb '08

05 Feb '08

The second annual Boost conference will take place in Aspen, Colorado, May 5-9. BoostCon is the main face-to-face event for all things Boost, from generic-programming techniques to Boost community, from using Boost libraries to writing Boost libraries, from deployment considerations to promoting the use of Boost more widely, from TR1 to TR2. Given the range and interests of last year's participants, the event again promises to be intense and in depth. We invite you to propose a session. See the BoostCon home page at www.boostcon.com for more information. Session formats Presentations focus on a practitioner’s ideas and experience with anything relevant to Boost and Boost users. Panels feature three or four people presenting their ideas and experiences relating to Boost's relevant, controversial, emerging, or unresolved issues. Panels may be conducted in several ways, such as comparative, analytic, or historic. Tutorials are formally prepared sessions at which instructors teach conference participants specific Boost-relevant skills. Workshops provide an active arena for advancements in Boost-relevant topics. Workshops provide the opportunity for experienced practitioners to develop new ideas about a topic of common interest and experience. Author's Corner Presentations focus on tips on usage and design. In addition, we're looking to uncover the hidden design gems hidden in boost libraries -- see below for more. Other formats may also be of interest. Don't hold back a proposal just because it doesn't fit into a pigeonhole. Session topics Topics of interest include, but are not restricted to, the following: * General tutorial sessions introducing one or more Boost libraries * In-depth sessions on using specific libraries * Case studies on using Boost * Experts panels * Advanced sessions on implementation techniques used within Boost libraries * TR1 (and TR2) * Development workshops to extend or enhance existing Boost libraries * Workshops on design process * Infrastructure workshops o Build tools o Website o Testing * C++0x and how it will change life for users and library writers * Concepts and Generic Programming * Other topics likely to be of great interest to Boost users and developers Interactive and collaborative sessions are encouraged, as this is the nature of both the online Boost community and the style of learning and participation that has proven most successful at such events. Sessions can be tutorial based, with an emphasis on interaction and participant involvement, or workshop based, whether hands-on programming or paper-based, discussion-driven collaborative work. Author's Corner Presentations Based on user feedback from last year, we'd like to encourage Boost library authors to do short sessions (typically 30 minutes) providing an overview of their libraries, tips on usage and design. In particular, we're looking to uncover the hidden design gems that underlie so many boost libraries. Standard outline for a presentation is as follows -- feel free to deviate as needed. * Library Purpose / Motivations * Library Genesis & History o why you developed it o when it was accepted o how it has evolved * Library Concepts * Library Usage Overviews and Tips * Library Design Decisions / Design Gems * Question / Answer Submitting a proposal Standard Sessions are 90 minutes. You may submit a proposal for fractions or multiples of 90-minutes. Fractional proposals will be grouped into 90 minute sessions covering related topics. Longer sessions, such as tutorials and classes, will be assigned 90 minute, three hour (i.e. half day), or six hour (i.e. full day) time slots. Please include: * The working title of the session * Type of session: presentation/panel/tutorial/workshop/other * A paragraph or two describing the session, suitable for the conference web site * Proposed length: 45/90 minutes, half/full day * Alternate length, if any: 45/90 minutes, half/full day * Audience: users/developers/both * Level: basic/intermediate/advanced * A biography, suitable for the conference web site * Your contact information (will not be made public) Please submit via email to conference at boost-consulting.com, with a subject that begins "BoostCon proposal" Timeline Proposals due As soon as possible. Proposals will be accepted on a first-come-first-served basis. Proposals acceptances sent As soon as accepted. Session materials due April 15, 2008. The session material go on the BoostCon CD handed out to attendees. Other arrangements Like Boost itself, BoostCon is strictly non-profit. Conference organizers are not paid for their time. Any surplus money will be rolled over into the succeeding year BoostCon budget. BoostCon provides free admission for all 90 minute and longer session presenters. This year we also hope to have enough revenue to pay presenters of longer sessions a small honorarium.

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boost::filesystem & working directories
by Robert Dailey 05 Feb '08

05 Feb '08

Is there a way to set the working directory for the entire application using boost::filesystem, or possibly another part of boost? I want to avoid using the Win32 API to do this.

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Re: [Boost-users] Another desperate request for help with a simple IOStreams sink and filter
by Chad Walters 04 Feb '08

04 Feb '08

>But when looking at the source of copy() I see there is no close() done at all. The "two stream" version of iostreams::copy() does instantiate exernal_closer for both the source and the sink, which should result in close() being called if they have the closable_tag in their category. I think your filters and devices do this based on what I can tell, but you may wish to verify that. >Is anyone actually using the library? I can't believe I'm the first > finding a bug like this in a 5 year old library. I did report a somewhat general problem with the close implementation which was biting me with certain filters: http://svn.boost.org/trac/boost/ticket/1002. Jonathan has recently fixed that problem. I am not sure this is related to your problem but you might want to see about applying those changes. If you are still having problems after that, I'd be happy to investigate further with you - I am pretty familiar with the close() implementation at this point. We are using iostreams quite extensively - the close issue mentioned above was the only problem that didn't turn out to be user error on our part. Chad On Feb 4, 2008 6:33 PM, Stefan Arentz <stefan.arentz(a)gmail.com> wrote: > I'm looking for some help with the following code where I try to > implement an aggregate filter and a sink. This super simple example is > supposed to print the xorred input but instead it prints: > > The result is: > do_filter > write: 01+x1+x,*!x76= > > Does anyone understand why the filtering and sink.write are not done > as part of the copy operation? The last two lines should be printed as > part of the copy process! It seems they are executed as part of > destructing these objects instead? I got a very useful hint on the #boost irc channel about this: calling out.reset() after the copy() made the code work correctly. I'm a confused about this though since the documentation of copy states: "The function template copy reads data from a given model of Source and writes it to a given model of Sink until the end of stream is reached. It then closes both components, using the function template close, and returns the number of characters written." But when looking at the source of copy() I see there is no close() done at all. Is anyone actually using the library? I can't believe I'm the first finding a bug like this in a 5 year old library. S.

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Review of Logging library begins today February 4th
by Gennadiy Rozental 04 Feb '08

04 Feb '08

The formal review of Logging library, proposed by John Torjo, begins today and will run till Feb 13: *Description/Motivation:* Applications today are becoming increasingly complex. Part of making them easier to develop/maintain is to do logging. Logging allows you to see what happened in your application. It can be a great help when debugging and/or testing it. The great thing about logging is that you can use it on systems in production and/or in use - if an error occurs, by examining the log, you can get a picture of where the problem is. Good logging is mandatory in support projects, you simply can't live without it. Used properly, logging is a very powerful tool. Besides aiding debugging/ testing, it can also show you how your application is used (which modules, etc.), how time-consuming certain parts of your program are, how much bandwidth your application consumes, etc. - it's up to you how much information you log, and where. *Online docs:* http://torjo.com/log2/doc/html *Download:* Package for download is available here: http://torjo.com/code/log2.zip (version v0.22.7 is targeted for review) or you can get the library from svn http://svn.boost.org/svn/boost/sandbox/logging/ *Compilation:* The Boost Logging Lib has been tested with the following compilers: VC 2005 VC 2003 gcc 3.4.2 gcc 4.1 Compiling using bjam is covered here: http://torjo.com/log2/doc/html/miscelaneous.html#misc_bjam What to include in Review Comments ================================== Your comments may be brief or lengthy, but basically the Review Manager needs your evaluation of the library. If you identify problems along the way, please note if they are minor, serious, or showstoppers. Here are some questions you might want to answer in your review: * What is your evaluation of the design? * What is your evaluation of the implementation? * What is your evaluation of the documentation? * What is your evaluation of the potential usefulness of the library? * Did you try to use the library? With what compiler? Did you have any problems? * How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? * Are you knowledgeable about the problem domain? And finally, every review should answer this question: * Do you think the library should be accepted as a Boost library? Be sure to say this explicitly so that your other comments don't obscure your overall opinion. Gennadiy Rozental - Review Manager -

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[SPAM:## 78%] [boost] Review of Logging library begins today February 4th
by Gennadiy Rozental 04 Feb '08

04 Feb '08

The formal review of Logging library, proposed by John Torjo, begins today and will run till Feb 13: *Description/Motivation:* Applications today are becoming increasingly complex. Part of making them easier to develop/maintain is to do logging. Logging allows you to see what happened in your application. It can be a great help when debugging and/or testing it. The great thing about logging is that you can use it on systems in production and/or in use - if an error occurs, by examining the log, you can get a picture of where the problem is. Good logging is mandatory in support projects, you simply can't live without it. Used properly, logging is a very powerful tool. Besides aiding debugging/ testing, it can also show you how your application is used (which modules, etc.), how time-consuming certain parts of your program are, how much bandwidth your application consumes, etc. - it's up to you how much information you log, and where. *Online docs:* http://torjo.com/log2/doc/html *Download:* Package for download is available here: http://torjo.com/code/log2.zip (version v0.22.7 is targeted for review) or you can get the library from svn http://svn.boost.org/svn/boost/sandbox/logging/ *Compilation:* The Boost Logging Lib has been tested with the following compilers: VC 2005 VC 2003 gcc 3.4.2 gcc 4.1 Compiling using bjam is covered here: http://torjo.com/log2/doc/html/miscelaneous.html#misc_bjam What to include in Review Comments ================================== Your comments may be brief or lengthy, but basically the Review Manager needs your evaluation of the library. If you identify problems along the way, please note if they are minor, serious, or showstoppers. Here are some questions you might want to answer in your review: * What is your evaluation of the design? * What is your evaluation of the implementation? * What is your evaluation of the documentation? * What is your evaluation of the potential usefulness of the library? * Did you try to use the library? With what compiler? Did you have any problems? * How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? * Are you knowledgeable about the problem domain? And finally, every review should answer this question: * Do you think the library should be accepted as a Boost library? Be sure to say this explicitly so that your other comments don't obscure your overall opinion. Gennadiy Rozental - Review Manager - _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/ listinfo.cgi/boost

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boost lambda weirdness (possible bug?)
by David Sankel 04 Feb '08

04 Feb '08

Hello, I'm trying to use boost lambda to create a function<void (const T&)> and I can't seem to get it to work. Here's the setup: class T { public: char m_c; T( char c ) : m_c( c ) { } virtual T * clone() const=0; virtual ~T(){} }; typedef boost::shared_ptr<T> TPtr; typedef std::vector<TPtr> TVec; using namespace boost::lambda; This works: const boost::function< void( T const * const) > f = bind( &TVec::push_back, &tVec, bind( constructor<TPtr>(), bind( &T::clone, _1))); But this doesn't: const boost::function< void( const T & ) > g = bind( &TVec::push_back, &tVec, bind( constructor<TPtr>(), bind( &T::clone, boost::cref(_1) ))); The compilation error I'm getting is that it cannot create a new object of type T and that is expected since T is abstract. Why would lambda be making copies instead of passing on the reference? I've attached a simplified version of the problem. Thanks, David -- David Sankel Sankel Software www.sankelsoftware.com 585 617 4748 (Office) 585 309 2016 (Mobile)

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building boost doc
by Christian Henning 04 Feb '08

04 Feb '08

Hi there, I just have a general question about the building boost documentation. Right now when building the trunk by just using the toolset option only dynamically linked libs using the release version code are being built. To specify static linked one need to add link=static to the command line. Can someone tell where to find such information in the documentation? Same question goes for all other options that I can apply to command line, like debug builds, etc. Thanks, Christian

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How to get the full path name of a file
by Ha Ha 04 Feb '08

04 Feb '08

With leaf(), I would only get file name like 1.doc. How could I get the full path name of a certain like c:\windows\1.doc. Thanks Haha

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