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Re: [boost] [msm] new version available
by Christophe Henry 06 Apr '10

06 Apr '10

> Christophe Henry wrote: >> Hi all, >> >> I just finished the newest MSM version. Unfortunately, I'm afraid I'm >> a bit late to get it shipped with boost v1.43 but at least it will >> give us time to have a look at it. >> What is new: >> - the doc was rewritten almost from the ground up. >> - internal transitions: for all front-ends, and both ways: either in >> the transition table or inside state's internal transition tables >> - more row types (yes, even more) allowing actions to be defined in >> state machines or in states >> The last 2 points aim at making states more useful >> > > Christophe - > > I'm looking forward to trying it out. > > michael I'm counting on your always very useful comments! Thanks, Christophe

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python/test/Jamfile.v2 help needed
by Ralf W. Grosse-Kunstleve 06 Apr '10

06 Apr '10

I've merged the current boost/python and libs/python trunk into the release branch, followed by this patch: Index: libs/python/test/Jamfile.v2 =================================================================== --- libs/python/test/Jamfile.v2 (revision 61033) +++ libs/python/test/Jamfile.v2 (working copy) @@ -184,8 +184,10 @@ # bpl-test bienstman5 ; # } -[ bpl-test calling_conventions ] -[ bpl-test calling_conventions_mf ] +# XXX disabled on release branch only, +# XXX to avoid failures on platforms other than Windows +# [ bpl-test calling_conventions ] +# [ bpl-test calling_conventions_mf ] # --- unit tests of library components --- Is it possible to have those two tests built and run only under Windows? Thanks! Ralf

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[GSOC2010] HEAPS & QUEUES draft proposal
by Alexandru Damian 06 Apr '10

06 Apr '10

Hello everyone, My name is Alexandru Damian. I am a second year student at the Polytechnic University of Bucharest, Romania. I am very interested in the Heaps & Queues idea, and with both a good programming and mathematical background, I believe that I can offer valuable ideas to this project. Below is a draft proposal for this. I didn't know what you would expect from such a proposal (talked to grafikrobot on freenode and he redirected me here), so the structures that are to be implemented are rather vague. If the proposal is on track, I will detail them. I have also talked so some guys on the irc channel about a more generic approach to trees and tries. What's your opinion on that (given that tree structures are already implemented in /intrusive)? I hope I'm not too annoying :). ***STUDENT PROPOSAL: HEAPS & QUEUES*** NOTE: My Student Proposal follows the template listed on: https://svn.boost.org/trac/boost/wiki/SoCSubmissionTemplate **PERSONAL DETAILS** NAME: Alexandru Damian UNIVERSITY: Polytechnic University of Bucharest MAJOR: Computer Science and Engineering DEGREE PROGRAM: B.Sc. EMAIL: alexdamian1989(a)gmail.com AVAILABILITY: According to the official timeline, there will be 11-12 weeks at my disposal: March 24 - August 9 (16). However, I plan to contract the "Community Bonding Period" to 2-3 weeks, so that I may have at least one week advance in coding. This will help me better organize my time during the summer, when I will be unavailable for about 2 weeks (in June) because of my exams. **BACKGROUND INFORMATION:** EDUCATIONAL & WORK BACKGROUND: I have been preparing in the fields of Computer Science and Mathematics since high-school when I have competed in numerous national and international competitions, gaining important experience and always finishing among the best. My interest in personal and professional growth has continued at university as well, with even better results at contests and scientific research. My work background and coursework have supplied me with many skills in theoretical computer science, data structures, algorithms and programming languages. In addition, I have broad experience in Mathematics and problem solving techniques. In the year 2009, I have worked at different projects for the Faculty of Automatic Control and Computers, including the research and development of a way to store and illustrate the temperature ratio in the University server room. The same year, I worked as a volunteer student consultant and I offered support in Mathematics for students taking the admission examinations. EXPRESSION OF INTEREST: Boost C++ Libraries has caught my attention in 2008, when I had my first important encounters with the Open Source Community. A library that offers more advanced data structures and algorithms than STL is needed on a daily basis when optimizing complex code. It is only natural for me to choose the "Heaps & Queues" project, as I have valuable experience in the algorithms that power these structures and their real-world applications. My plans for further support and development of the Boost C++ Libraries will extend even after the GSOC deadline, with plans to implement more algorithms supplementary to the work done during the summer and in other areas (such as the BigInt idea, or AI algorithms: neural networks, genetic algorithms, fuzzy systems etc.). PROGRAMMING SKILLS: Strong background in theoretical computer science, algorithms, data stuctures and optimization . Strong background in advanced mathematics. Programming Languages: C (4/5), Java (4/5), C++ (3/5), C# (3/5), Shell scripting (2/5), ASM (2/5). Other programming languages and their proficency levels are illustrated in the Resume. **PROJECT PROPOSAL** ABSTRACT The purporse of this project is to create a library that involves heap and queue creation and manipulation. This will be very useful in implementing more complex algorithms or data structures that take advantage of these structures (a basic example is Dijkstra's shortest path algorithm). The library will include basic implementations of heap structures (i.e. binary heap) and queues, as well as the more complex (and more relevant) structures. PROJECT CONTENTS The current version of the Libraries has little support for heaps and queues. Therefore, the following will be implemented, with a discussion on every structure's difficulty, speed and memory used. Firstly, a well-known table of complexities for the binary min(max)-heap: findMin(findMax) : O(1) | deleteMin(deleteMax) : O(log N) | insert : O(log N) | merge : O(N) * D-ARY HEAP : a more general implementation of the binary heap (2-ary heap). The main advantage a d-ary heap has is that insertion will be significantly faster, requiring a theoretical O(log_d N) operations. However, finding an element's parent is rather difficult if d is not a power of 2, since we can not use bitwise shifting operations. However, delete-min is slower, because of the d-1 comparisons to find the minimum value, using a standard algorithm (probable fix: use a min-heap). * BINOMIAL HEAP, BINOMIAL TREES : a mergeable heap; although the complexity for findMin(findMax) is O(log N), this heap, along with the ones below (also mergeable), offer a better complexity for merge : O(log N). Since binomial heaps use binomial trees, this data structure will also be implemented. * FIBONACCI HEAP : another mergeable heap, with better amortized time complexity than the binomial heap * RELAXED HEAP, RELAXED FIBONACCI HEAP (an idea at: http://www.google.ro/url?sa=t&source=web&ct=res&cd=1&ved=0CAYQFjAA&url=http…) * SKEW HEAP : a structure that is easier to merge than a binary heap, but is unbalanced. This could be considered optional, as it is a median option between d-ary heaps and mergeable heaps (binomial, fibonacci). * TREAP : although treaps are already implemented, they should be adapted to use the new heap library. * QUEUE : a basic implementation of the queue structure (possibly use the STL container) * DEQUEUE : although an implementation already exists /fusion/container, that has to be documented. A new implementation using the generic queue structure mentioned above. * PRIORITY QUEUE : implemented with the use of a heap. * BUFFER (CIRCULAR QUEUE) : fixed size, circular queue (if queue is full, the oldest data is overwritten). Such a queue could be used to implement a structure similar to RRDs. * (BONUS) SKIPLISTS : randomized search structure. * (BONUS) B-TREES : extended binary trees with excellent complexity when comparisons are not the most time-consuming operations. * (BONUS) INTERVAL TREES : extended complete binary trees supporting fast segment intersection queries. Some of these structures can use a fixed size array (use /boost/array). However, it would be good to eliminate the constraints of fixed size arrays. This will require using STL's <vector> or, should it be decided not to include a binary, a local implementation of it, i.e. ARRAY LIST. TIMELINE As stated above, I would like to start with an advance of one week (May 17). WEEKS -2, -1, 0 (April 26 - May 16) : Community Bonding Period These three weeks will offer me the possibility to accomodate with the code, the coding conventions and the community. During these 3 weeks, I will also discuss with the organization whether binary libraries should be included or proprietary structures should be implemented (variable sized arrays, basic queue, basic priority queue (heap)). Modifications in the timeline (reordering, additions, deletions) can also occur. Finally, I will decide if I clean up the implementations from /pending (i.e. queue, fibonacci_heap, relaxed_heap, etc.) or create new structures, based on the newly implemented structures. Implement some simple structures so as to better get used to the code (probably ARRAY LIST or BINARY HEAP). WEEK 1 (May 17 - May 23) : Implement D-ARY HEAP, BINARY HEAP (2-ARY HEAP). Decide whether to first implement the d-ary heap and then the binary heap as a particular case, or implement the binary heap first, and after that the d-ary heap, associating a binary min(max)-heap to each array of children; solve the excess memory. WEEKS 2, 3 (May 24 - June 6) : Implement BINOMIAL TREES, BINOMIAL HEAPS, FIBONACCI HEAPS (don't adapt, usage for relaxed fibonacci heaps), RELAXED HEAPS and RELAXED FIBONACCI HEAPS. Official start of the coding phase. All of these heaps follow the same basic ideas, therefore progress should be relatively easier after the binomial heaps are implemented. Initial algorithms will probably be those specified (and variations) in Cormen or Knuth, as well as the idea suggested in the above mentioned link. WEEKS 4, 5 (June 7 - June 20) : University Exams WEEKS 6, 7 (June 21 - July 4) : Fix any problems with previous heaps. Implement SKEW HEAPS. Adapt TREAPS. WEEKS 8, 9 (July 5 - July 18/16) : Add mutable behaviour to the heaps. Apply optimizations. Create some automated tests. Week 8 will mark the mid-term evaluation deadline. The objective is to complete HEAP structures. The timeline offers roughly 2 weeks for bug fixing, so that should be enough. WEEK 10 (July 19 - July 25) : Implement QUEUE, DEQUEUE. WEEK 11 (July 26 - August 1) : Implement CIRCULAR QUEUE, PRIORITY QUEUE. WEEK 12 (August 2 - August 8) : Fix bugs related to the QUEUE structures. Add mutable behaviour to the queues. Apply optimizations and custom algorithms for fixed-length data types. Create automated tests. WEEK 13 (August 9 - August 16): Finalize code and documentation. NOTES: 1. The Exams period is, actually, 4 weeks (June 7 - July 5), comprising 5 exams. However, I should be able to compress the total time to only 2 weeks by moving some of my studying in May. 2. Weeks 6 and 8 are reserved for fixing heap bugs. Should there be less problems than expected, I can gain one bonus week. 3. If we choose to implement the structures using STL binaries, I could gain one more bonus week from weeks 1, 10 and 11. 4. With (2) and (3) in mind, I could implement any of the bonuses written above (at the end, if everything else is complete). a) SKIPLISTS : a randomized search structure with very good practical complexity. b) INTERVAL TREES : given the already implemented Interval structure (/numeric/interval), it would be nice to have such a structure, for easy geometric intersection queries. c) B-TREES : adaptation of the Balanced Binary Trees, typically used in situations where the comparison operation is not the most time consuming one (disk seeking). WORK FLOW I plan to organize my time and coding in such a manner that I am able to post changes on a forum / blog every 4 days (except the period with exams). That means roughly 2 times per week, as I will have no problem working in weekends. TODO Cheers, -- Alexandru Damian Polytechnic University of Bucharest Faculty of Automatic Control and Computers

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boost.graph
by Piyush Garg 06 Apr '10

06 Apr '10

What is the best representation of graph in memory that is compatible with other libraries used in the boost? Can we implement connectives in any way?

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[mpl] is_macro_called
by Lorenzo Caminiti 06 Apr '10

06 Apr '10

Hello all: Is there a way I can check at compile-time and class-scope if a macro has been called and expanded (at least one time) from within a member function? For example: #define X(...) ... // Some macro definition -- the macro parameters could be anything needed to implement is_macro_called. struct is_macro_X_called { ... }; // Some implementation -- this could be a template or something else. So that: struct z { void f() { X(...); // Macro called from within a member function. } // Detect at class-scope and a compile-time that the macro was called. static const bool is_macro_X_called::value; // Evaluates to true. }; Instead: struct z { void f() { // X(...); // Macro not called. } static const bool is_macro_X_called::value; // Evaluates to false. }; I do not know how to program this. However, could for example the macro X() instantiate a template with some special template parameter that can then be inspected at compile-time by a is_macro_called metafunction? Thank you very much. Lorenzo

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[Boost.process] GSoc proposal
by Kasra 05 Apr '10

05 Apr '10

Hi, I have decided to polish up the current boost.process this summer. It has been on the list far too many times without much further progress. After checking out the code I've begun working, so I need to start working on the new API which I intend to be similar to boost.thread. Are there any volunteering mentors? class process { class id; class status; class priority; typedef std::bitset<?> affinity_type; static process& this_process(); static std::vector<process> processes(); static std::vector<process> processes(const std::string& machine); static std::vector<process> processes_by_name(const std::string& name); static std::vector<process> processes_by_name(const std::string& name, const std::string& machine_name); static process start(const std::string& proc); static process start(const std::string& proc, const std::string& params); const id& get_id() const throw(); void terminate(bool kill = false ); status wait(); status idle_wait(); const boost::posix_time::ptime& start_time() const; affinity_type processor_affinity() const throw(); void processor_affinity(const affinity_type& affinity); const priority& priority() const throw(); void priority(const priority& new_priority) const throw(); postream& standard_input() const; pistream& standard_output() const; pistream& standard_error() const; boost::posix_time::time_duration kernel_time() const; boost::posix_time::time_duration user_time() const; boost::posix_time::time_duration total_time() const; const void* max_working_set() const; void max_working_set(const void* value); const void* min_working_set() const; void min_working_set(const void* value); uintmax_t peak_paged_memory() const; uintmax_t peak_private_memory() const; uintmax_t peak_virtual_memory() const; uintmax_t peak_working_memory() const; uintmax_t paged_system_memory() const; uintmax_t paged_memory() const; uintmax_t private_memory() const; uintmax_t virtual_memory() const; uintmax_t working_memory() const; }; With Best Regards Mr. Kasra Nassiri Department of Computer Science Imperial College London

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Re: [boost] python/test/Jamfile.v2 help needed
by Ralf W. Grosse-Kunstleve 05 Apr '10

05 Apr '10

I think I figured it out: I moved the new "rule" block up in Jamefile.v2 . Now monitoring the build summaries again... Ralf ----- Original Message ---- From: Ralf W. Grosse-Kunstleve <rwgk(a)yahoo.com> To: boost(a)lists.boost.org Sent: Mon, April 5, 2010 1:05:20 PM Subject: Re: [boost] python/test/Jamfile.v2 help needed The recent build summaries for boost.python come up all blank. I'm guessing this is a bad sign. Are the log files somewhere from which I could tell what's wrong? Given boost svn trunk, I found out I can run bootstrap.sh to get a bjam executable. But I couldn't figure out how to build and run the python tests. Could some help with the commands I need? I have Fedora 6, 8, 11, 12. Ralf ----- Original Message ---- From: Vladimir Prus <ghost(a)cs.msu.su> To: boost(a)lists.boost.org Sent: Sat, April 3, 2010 11:21:04 PM Subject: Re: [boost] python/test/Jamfile.v2 help needed Ralf W. Grosse-Kunstleve wrote: > I've merged the current boost/python and libs/python trunk into the release branch, > followed by this patch: > > Index: libs/python/test/Jamfile.v2 > =================================================================== > --- libs/python/test/Jamfile.v2 (revision 61033) > +++ libs/python/test/Jamfile.v2 (working copy) > @@ -184,8 +184,10 @@ > # bpl-test bienstman5 ; > # } > > -[ bpl-test calling_conventions ] > -[ bpl-test calling_conventions_mf ] > +# XXX disabled on release branch only, > +# XXX to avoid failures on platforms other than Windows > +# [ bpl-test calling_conventions ] > +# [ bpl-test calling_conventions_mf ] > > # --- unit tests of library components --- > > > Is it possible to have those two tests built and run only under Windows? Yes. Create a function as follows (in your Jamfile): rule require-windows ( properties * ) { if ! <target-os>windows in $(properties) { return <build>no ; } } then, in requirements of your tests, use <conditional>@require-windows, e.g: [ bpl-test calling_conventions : : <condiitonal>@require-windows ] Note that cygwin is a different OS from windows, so if the test must be run on cygwin, you need to adjust conditional accordingly. Does this help? - Volodya _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

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Re: [boost] [msm] new version available
by Christophe Henry 05 Apr '10

05 Apr '10

>>> Hi, >>> >>> Just a form remark. We use to see the code highlighted. Have you the possibility to highligth the code? >>> >>> Best, >>> Vicente >>> >> >> Probably. I just need to find out if there is another DocBook tag for >> this. At the moment, I'm using <code>. >> I'm not a BocBook expert, but if one reads this, please help ;-) > > I have never used DocBook but I have found that http://www.sagehill.net/docbookxsl/SyntaxHighlighting.html. > > There are some uses of <programlisting> already in Boost.Function. > > Hoping this helps > Vicente Oh yes it does. And it looks much better, you're right. Great! Then it'll be done fast. Thanks a lot, Christophe

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[Log] Problem with attributes + gcc -fvisibility=hidden
by Tony Astolfi 05 Apr '10

05 Apr '10

I'm evaluating boost::log for use in a project I'm working on, and I found a potential issue. If I compile my program using gcc with the '-fvisibility=hidden' option enabled, then some log event attributes don't show up in the output. For example: #include <boost/log/attributes/clock.hpp> #include <boost/log/common.hpp> #include <boost/log/utility/init/to_console.hpp> int main () { boost::log::init_log_to_console( std::cout, boost::log::keywords::format = "[%TimeStamp%] %_%" ); boost::log::core::get()->add_global_attribute( "TimeStamp", boost::make_shared< boost::log::attributes::local_clock >() ); boost::log::sources::logger l; BOOST_LOG( l ) << "Error!"; return 0; } Output: % g++ main.cpp -I../../../glnxa64/include -L../../../glnxa64/lib -lboost_log -lboost_system -lboost_log_setup && ./a.out [2010-Apr-05 12:39:14.872961] Error! % g++ main.cpp -I../../../glnxa64/include -L../../../glnxa64/lib -lboost_log -lboost_system -lboost_log_setup -fvisibility=hidden && ./a.out [] Error! I've found issues like this in the past caused by boost libraries not marking certain types as export-visibility, resulting in a failure later on to match two type-id objects that ought to be identical. Could something like this be happening in the recently accepted Boost.Log library? Is this something the author would be interested in fixing/supporting?

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Re: [boost] [msm] new version available
by Christophe Henry 05 Apr '10

05 Apr '10

> Hi, > > Just a form remark. We use to see the code highlighted. Have you the possibility to highligth the code? > > Best, > Vicente > Probably. I just need to find out if there is another DocBook tag for this. At the moment, I'm using <code>. I'm not a BocBook expert, but if one reads this, please help ;-) Christophe

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[test] How to have a simple unit test compile on Borland/CodeGear?
by Niels Dekker - address until 2010-10-10 05 Apr '10

05 Apr '10

Is the following still a proper way to write a unit test for a Boost library component? #define BOOST_INCLUDE_MAIN #include <boost/test/test_tools.hpp> int test_main(int, char*[]) { // TODO Some testing here... return 0; } I can't get the above code compiling on the latest Borland/CodeGear compiler (Embarcadero C++ 6.21), installed by c++builder_2010_3615_win_esd.zip, downloaded from www.embarcadero.com/downloads Even though I already patched boost/smart_ptr (ticket #4067) and boost/exception (ticket #4068). I just do: bjam toolset=borland Which tries to compile <boost/test/utils/runtime/cla/dual_name_parameter.hpp> apparently, and it yields an error at line 43: template<typename Modifier> void accept_modifier( Modifier const& m ) { if( m.has( prefix ) ) { set_prefix( m[prefix] ); // line 43, "Error E2094"! ... The complete error message is down here. Interestingly, the message says that operator+ is missing (while I don't see a need for operator+ in this context). Any help is appreciated! Kind regards, Niels ------------------------------------------------------------ CodeGear/Embarcadero C++ 6.21 output: Error E2094 ..\..\..\..\boost/test/utils/runtime/cla/dual_name_parameter.hpp 43: 'operator+' not implemented in type 'nfp::nfp_detail::named_parameter_combine<nfp::named_parameter<const unit_test::const_string,description_t,const unit_test::const_string &>,nfp::nfp_detail::named_parameter_combine<nfp::named_parameter<bool,optional_t,bool>,nfp::nfp_detail::named_parameter_combine<nfp::named_parameter<bool,guess_name_t,bool>,nfp::nfp_detail::named_parameter_combine<nfp::named_parameter<const unit_test::const_string,separator_t,const unit_test::const_string &>,nfp::named_parameter<const unit_test::const_string,prefix_t,const unit_test::const_string &> > > > >' for arguments of type 'nfp::typed_keyword<unit_test::const_string,prefix_t,0>' in function void dual_name_policy::accept_modifier<nfp::nfp_detail::named_parameter_combine<nfp::named_parameter<const unit_test::const_string,description_t,const unit_test::const_string &>,nfp::nfp_detail::named_parameter_combine<nfp::named_parameter<bool,optional_t,bool>,nfp::nfp_detail::named_parameter_combine<nfp::named_parameter<bool,guess_name_t,bool>,nfp::nfp_detail::named_parameter_combine<nfp::named_parameter<const unit_test::const_string,separator_t,const unit_test::const_string &>,nfp::named_parameter<const unit_test::const_string,prefix_t,const unit_test::const_string &> > > > > >(const nfp::nfp_detail::named_parameter_combine<nfp::named_parameter<const unit_test::const_string,description_t,const unit_test::const_string &>,nfp::nfp_detail::named_parameter_combine<nfp::named_parameter<bool,optional_t,bool>,nfp::nfp_detail::named_parameter_combine<nfp::named_parameter<bool,guess_name_t,bool>,nfp::nfp_detail::named_parameter_combine<nfp::named_parameter<const unit_test::const_string,separator_t,const unit_test::const_string &>,nfp::named_parameter<const unit_test::const_string,prefix_t,const unit_test::const_string &> > > > > &)

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[cpp0x] Macro to support some C++0x syntax and functionality
by Lorenzo Caminiti 05 Apr '10

05 Apr '10

Hello all, Consider the following C++0x-like example (inspired by ConceptC++ http://www.generic-programming.org/languages/conceptcpp/tutorial/ and C++ Contract Programming proposal n1962): // Example strangely uses pointers instead of iterators just to have preconditions. template<std::CopyConstructible T> requires Addable<T>, Assignable<T> // Concepts. precondition { first; last; } // Pointers not null. postcondition (total) { total == result; } // Returning result. T sum(T* first, T* last, T result) { for (; first != last; ++first) result = result + *first; return result; } What do you think of the following macro that implementes this in ISO standard C++ while keeping the above C++0x-like syntax by wrapping it within a preprocessor sequence? BOOST_CPP0X_FUNCTION( (template)( (std::CopyConstructible)(T) ) (requires)( (Addable<T>) (Assignable<T>) ) (precondition)( (first) (last) ) (postcondition)(total)( (total == result) ) (T) (sum)( (T*)(first) (T*)(last) (T)(result) ) ({ for (; first != last; ++first) result = result + *first; return result; }) ) The idea is that using the preprocessor I can parse the specified signature-sequence so I have all the tokens I need to declare/define the C++ function plus I can add the concepts (Boost.Concept), contracts (Boost.Contract), named parameters (Boost.Parameter), etc. Furthermore, the syntax of signature-sequence can be any valid preprocessor sequence that uses words (but not symbols) for keywords -- e.g., (requires) and (preconditions) are OK but (=) is not. This way I can define the signature-sequence syntax to closely match the syntax of C++0x (for concepts) and of other C++ standard proposals (like n1962 for contracts). DISCLAIMER: I think this is possible but I would need to try to implement it in order to be 100% sure and to identify possible limitations. Regards, Lorenzo P.S. I started considering this in reference to a previous email thread "Re: [boost] [contract] Contract Programming Library": On Sat, Feb 13, 2010 at 9:44 AM, Lorenzo Caminiti <lorcaminiti(a)gmail.com> wrote: > On Fri, Feb 12, 2010 at 3:39 AM, Andrzej Krzemienski <akrzemi1(a)gmail.com> wrote: >> I would be very interested in trying such a library. I have one >> it is inevitable, etc., but.. read on. I know at least one library in >> Boost that also spoils function declarations in order to provide >> additional functionality: Concept Check library; they may be others >> too (MPL?). >> My suggestion is that if there are (or will be) libraries that require >> spoiling function declarations, they should all provide the same >> "spoiled" syntax. Otherwise I will be always asking "how do I declare >> a function in this library?". It would be very convenient if Boost >> provided one alternative function definition syntax that when used >> would enable all its libraries to work. > I agree. However, in the past I did look into harmonizing my library > API with the ones of Boost.ConceptCheck and/or Boost.Parameter but it > did not seem feasible... I will double check it.

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[google summer of code] student
by Cezary Bartoszuk 05 Apr '10

05 Apr '10

Hello, I am a CS student and I would like to patricipate in developing Heaps & Queues in Boost during Google Summer Of Code '10. Where, besides the source code, should I search for information about what's already in Boost (in the meaning of heaps/queues)? Who should I talk to about participating in Boost? Best regards, Cezary Bartoszuk, --- Faculty of Mathematics Informatics and Mechanics, University of Warsaw, Poland

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Interested in Boost.Graph
by Piyush Garg 05 Apr '10

05 Apr '10

hi I am interested in upgrading the boost graph library to parallel boost graph library. I want to ask that do i have to chose one of the projects in boost.graph or i have to make them all during summer. Can i make the project on that or i have to suggest my own idea? Thanks Piyush Garg.

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[GSoC] data structures library for summer of code 2010
by Dan Fox 05 Apr '10

05 Apr '10

Hi everyone, My name is Daniel Fox. I'm interested in working on making the advanced data structures library project idea for this year's Google Summer of Code. I've spent some time looking at the current structures in boost/pending and I believe I have an idea of what I would like to do for it.

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[string_algo] first_finderF hoist empty check out of loop
by Jeff Flinn 04 Apr '10

04 Apr '10

In trying to get string algorithm icontains to work with spirit's file_iterator (which I still haven't been successful with) I noticed that the check for an empty search string is in side the loop. As: // Outer loop for(input_iterator_type OuterIt=Begin; OuterIt!=End; ++OuterIt) { // Sanity check if( boost::empty(m_Search) ) return result_type( End, End ); Wouldn't it be better to hoist this check out of the loop and only do it once? Thanks, Jeff

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Semantic graphs for GSOC 2010
by Alexander Golec 03 Apr '10

03 Apr '10

Hey all, My name is Alexander Golec, and I'm a student at Fordham University studying mathematics, transferring to Columbia University to study CS engineering. I would like to ask about some specifics of the heaps and queues project. Have the items to be added to the advanced data structures library already been decided? How are the structures coupled to the BGL? Also, I would like to implement the binomial heap structure. Would anyone have any pointers for getting to know Boost's internals? Thanks, Alex

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GSOC Bigint Proposal.
by swagat konchada 03 Apr '10

03 Apr '10

I would like to receive comments on my proposal for Bigint this year. To design, implement, test and document an expression template system("a wrapper for swappable Bigint providers") for the Boost.bigint around NTL, GMP(Is there enough interest around Xint?) in view of the numeric_adaptor scheme developed by Barend Gehrels in providing as many possible operators as possible. My mid-term examinations are going on and It's being impossible for me to hang around the list and study about Xint. I hope you understand... :)() -- Problem is a phenomenon indicating lack of thought. Swagat Konchada

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GSoC: Enforcing Code Feature Requirements
by vicente.botet 03 Apr '10

03 Apr '10

Hi, I have recently reread the article "Enforcing Code Feature Requirements in C++" by Scott Meyers <http://www.artima.com/cppsource/codefeaturesP.html> I have posted some ideas that could improve the design (<http://www.artima.com/forums/flat.jsp?forum=226&thread=238798&start=0#372622>) I wanted to know if this could be a good subject for GSoC, if the approach I purpose to solve some issues is acceptable and if there is some students interested. Of course any comments are welcome. Best, _____________________ Vicente Juan Botet Escribá

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Re: [boost] [range] Permission to merge to the Release branch
by Beman Dawes 03 Apr '10

03 Apr '10

On Fri, Apr 2, 2010 at 12:27 PM, Neil Groves <neil(a)grovescomputing.com> wrote: > Beman, > > I am seeking permission to merge the trunk version of Boost.Range into the > release branch. The regression test results have not detected new > regressions, however there are a number of the new features that are not > passing unit tests on several compilers. Since the new features would not be > usable if I did not merge my opinion is that it is worth merging to allow > the use of the newer features on more compliant compilers. In the meantime I > can seek to improve the support of adaptors and algorithms on the less > capable compilers. Go ahead and merge. For the tests that are expected to fail (because of older compilers, or whatever), please mark them up as expected failures. Ask if you need help with the markup. > > Of course, I respect that being a newbie to the Boost development and > release process that I may not be making the most informed judgement and > hence I respectfully seek your guidance. It is best to ask such questions on the main list. That allows others to comment, and if I'm not available one of the other release managers can reply. Thanks, --Beman

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Graph class, an idea
by Alexander Golec 03 Apr '10

03 Apr '10

Hey all, I have recently been working on a project that has led me to some interesting ideas for a graph class. Chief among them is the structure of the cycle matrix. This is a matrix representing the fundamental cycles of a graph. With this matrix, one can easily determine if, given an arbitrary set of vertices, if there is a cycle that passes through all of them. Whats more, it can easily provide that cycle if it exists. I'd like to ask if this sounds like something that would be useful in Boost's Graph class. Thanks, Alex

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Re: [boost] [GSoC 2010]: BGL Graph Connectives ideas
by Yaroslav Vorontsov 03 Apr '10

03 Apr '10

>> > I have some ideas about implementing graph connectives. I think that the >> > best way to implement first four binary operations (union, join, >> > intersection and difference) is to use adjacency matrices. >> > >> > I think variants of these algorithms for non-adjacency matrices are just as > important. It would be best to focus on these problems and their generic > solution than to propose more solutions for a smaller set of graphs. > OK, let it be so. The implementation of graph connectives using the adjacency matrices isn't too difficult. Regarding adjacency lists or incidency matrices, it's more difficult and intererestring to perform such operations. I meant that it's more convenient to do the operations for adjacency matrices and then to convert them into another graph representation, but now I doubt that this will be more effective (it needs some time to convert a graph from one representation to another (and a lot of memory), and the algorithm needs time and memory, too).

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Re: [boost] Boost Digest, Vol 2869, Issue 5
by Yaroslav Vorontsov 03 Apr '10

03 Apr '10

>> > I have some ideas about implementing graph connectives. I think that the >> > best way to implement first four binary operations (union, join, >> > intersection and difference) is to use adjacency matrices. >> > >> > I think variants of these algorithms for non-adjacency matrices are just as > important. It would be best to focus on these problems and their generic > solution than to propose more solutions for a smaller set of graphs. > OK, let it be so. The implementation of graph connectives using the adjacency matrices isn't too difficult. Regarding adjacency lists or incidency matrices, it's more difficult and intererestring to perform such operations. I meant that it's more convenient to do the operations for adjacency matrices and then to convert them into another graph representation, but now I doubt that this will be more effective (it needs some time to convert a graph from one representation to another (and a lot of memory), and the algorithm needs time and memory, too).

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A Pimpl variant
by vicente.botet 03 Apr '10

03 Apr '10

Hi, I don't know if this is the correct ML to talk about this subject, but as there was recently a discussion about wether Boost should or not use Pimpl, I have decided to post this here. In http://www.gotw.ca/publications/mill05.htm H. Sutter states "There are four main alternative disciplines: 1. Put all private data (but not functions) into XImpl. 2. Put all private members into XImpl. 3. Put all private and protected members into XImpl. 4. Make XImpl entirely the class that X would have been, and write X as only the public interface made up entirely of simple forwarding functions (another handle/body variant)." My experience is that I add more private member functions than private member data. I have explored a different variant 5. Put all private funtion and static data (but not instance data) into XImpl. XImpl needs only to store the back pointer. While this approach doesn't encapsulates all the private members has some advantages: * The XImpl class has no inherent instance data, so no space overhead * The class doesn't needs to store any XImpl pointer as there is no data to maintain, so no need to allocate/deallocate it. * Reduce the performance overhead of the Pimpl idiom. The drawbacks are: * Need to include the headers needed for the private instance data. * There is yet a minimal performance overhead on the construction of the temporary XImpl class and the derreference of the back pointer. Next follows an implementation exaple. * Grant friend access to the private implementation class class C { public: void f(); void g(); protected: // ... private: struct impl; friend struct impl; // the private part contains only instance data and virtual functions int priv; }; * Identify the private functions and the private static data and put them on the implementation class struct C::impl { C::impl(C* thisC) : that(*thisC) {} void ifct() { that.priv = ... // use of private data that.g(); // call to a public function jfct(); // call another private function } C& that; static int icount; }; * Prefix all the ex private function calls by impl(this) impl(this).ifct(); * Access without constraints the impl static data impl::icount; There is a proposal from Francis Glassborow, N1742: Auxiliary class interfaces:<http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2004/n1742.pdf> that address this problem in a general context. What do you think of this variant? Best, _____________________ Vicente Juan Botet Escribá

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[lambda] [result_of] Lambda enhancements
by Adam Butcher 03 Apr '10

03 Apr '10

Hi Perhaps this would have been better as two separate mails but since it is all lambda related I have included it as one (despite one patch actually being to the result_of library). [lambda] I discovered recently that member-function-ptrs wrapped in boost::lambda objects do not apply directly if the subject is held in a smart-ptr (unless that smart-ptr has an implicit conversion to T*). There are a number of places in our code base where we have worked around this by using something like *free1 rather than simply free1 which ends up calling the 'apply member-function to object-by-reference' adaptor. This works providing the smart-ptr defines a type 'element_type' to be the underlying object type (as shared_ptr et al do). It does not work for third-party smart-ptrs that do not define this type. It struck me that since boost.bind uses boost.mem_fn's get_pointer template to handle this use case it would be reasonable to add an overload of 'apply' to lambda/detail/function_adaptors.hpp that deferred to that. I knocked up a perl script which adds the necessary overloads to each specialization in function_adaptors which I have attached (I have also attached the resulting diff). It may be that this yields some unpleasant side-effects that I haven't thought of or observed but so far it seems to work okay with our code base. The get_pointer overload is disabled if the argument is convertible to ref-to-const-object-type (e.g. if it is a derived type) since then the reference overload should be used. I would appreciate any feedback on the idea and implementation. [result_of] Whilst implementing a front-end template for a set of functions that accept boost.function objects with various return types, I discovered that boost.result_of does not implement support for the nested sig<tuple> template used by boost.lambda objects. My intent was to accept any user-supplied function at the front-end and, based on the given function's return type when applied to a specific set of arguments, forward to the appropriate implementation. This determination currently fails if the user supplies a lambda object. The attached result_of patch adds detection of the nested sig template in order to support determining the return type of lambda functions (providing the necessary arguments are given). This is done in a non-intrusive way; i.e. there is no physical dependency on boost.lambda or boost.tuple, though the boost.tuple classes 'cons' and 'null_type' are forward declared. Since they are only ever instantiated when a boost.lambda object is provided (which will have already brought in their definitions) I think it should be okay. In order to provide the sig template with its required tuple, a facility has been added (with implementation generated by some additional preprocessor code) that converts from function-type to tuple (i.e. F(A,B...) -> cons<F,cons<A, cons<B,...null_type>>>). Since only the type declarations are required this can be done without pulling in any tuple headers. One thing I am a little concerned about is that the determination mechanism for the existence of the sig template is probably not very portable (I have only tried it on GCC 4 and VC9). Is there an MPL/type_traits predicate generator for portable nested template detection? I am aware of BOOST_MPL_HAS_XXX_TRAIT_(NAMED_)DEF but I couldn't see any generator around that area that would do nested template detection. We have such a facility in our code base but it will have only been tried on GCC 4 and VC9 (maybe also VC7.1). Again I would appreciate any feedback on these diffs and whether or not they are suitable for inclusion into the respective libraries. Regards, Adam

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