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Boost license / OSI approved
by Ruediger Berlich 01 Oct '07

01 Oct '07

Hi there, I noticed that the Boost license is not listed as an OSI approved license (see here: http://www.opensource.org/licenses/alphabetical ). Why is this ? The license seems to nicely comply with the Open Source definition, from what I can see (see http://www.opensource.org/docs/osd) http://www.fsf.org/licensing/licenses/ lists it as GPL-compatible. Best Regards, Ruediger

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thread, use case: one manager and several worker threads
by Torsten Mohr 01 Oct '07

01 Oct '07

Hi, i have a question regarding boost::thread on general usage. I have a calculation intense problem that can be parallelised quite well. But i'd like the whole thing to be interruptible, so when the user commands to stop calculationg then the threads should stop working on the problem. I don't know how to set this up in principle, some thoughts: I want to create one manager thread and several worker threads. The manager thread commands the worker threads on what job to work. When a worker thread has finished, it tells the manager thread so and can get another job to work on. If a user commands the manager thread to stop working, the manager thread commands the worker threads to stop as soon as possible. I think these are quite some normal requirements, but i don't know how to implement this using boost::thread. What is the preferred way to send commands to threads? Just lock a mutex that is shared with the thread and then write a shared variable? How can a manager thread wait on several worker threads at once without wasting CPU time? How does a worker thread notify the manager thread? I can't see how this can be done with boost::condition, do i miss something? Or is it possible for the worker thread to share a boost::mutex with every worker thread, let the manager thread lock those mutexes? It then can only do "condition->wait" on _one_ of the conditions. Best regards, Torsten.

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one reason I suspect a build problem in prior post,
by Mike Marchywka 01 Oct '07

01 Oct '07

when I added the code to trap the regex_error, the previously clean build returned the following during linking but I didn't think it would be a problem: Info: resolving vtable for boost::regex_errorby linking to __imp___ZTVN5boost11r egex_errorE (auto-import) I'm linking to /libboost_regex-gcc-mt-1_33_1.a and cygboost_regex-gcc-mt-1_33_1.dll Thanks again. [ I decided to add boost while using my mom's machine and I found out I had accidentally included boost in "her" cygwin install so it is quite likely I botched something ] Mike Marchywka 586 Saint James Walk Marietta GA 30067-7165 404-788-1216 (C)<- leave message 989-348-4796 (P)<- emergency only marchywka(a)hotmail.com Note: Hotmail is blocking my mom's entire ISP claiming it is to reduce spam but probably to force users to use hotmail. Please DON'T assume I am ignoring you and try me on marchywka(a)yahoo.com if no reply here. Thanks. _________________________________________________________________ Test your celebrity IQ. Play Red Carpet Reveal and earn great prizes! http://club.live.com/red_carpet_reveal.aspx?icid=redcarpet_hotmailtextlink2

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date_time time_duration getting milliseconds
by Sebastian Hauer 01 Oct '07

01 Oct '07

Hi Boost Users, I've started using boost's date_time library recently which I find quite convenient for the most part. I have to handle times with sub second parts frequently and was wondering what the recommended way is to extract the milliseconds part of a time_duration instance? It seems there is no time_duration.milliseconds() method available and fractional_seconds() is platform dependent. BTW: I am currently using boost 1.34.1. Regards, Sebastian

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u32regex_search crashes
by Anjaly 01 Oct '07

01 Oct '07

Hello, I am new to Boost-regex library. The libray is build with icu support.The user interface is created using wxWidgets library. I want to search a file using u32regex_search. But the program crashes and the error it shows is 'Invalid UTF-8 sequence encountered while trying to encode UTF-32 character'.I am reading the contents of the file and it is stored in char array.The program is crashing when it encounters a char with hex value 00. wxString s=SearchTxt->GetValue(); const char *start=(const char*)buffer; const char *end=(const char*)buffer+len; boost::cmatch what; boost::u32regex e1= boost::make_u32regex(s.fn_str(), boost::regex::icase); while(boost::u32regex_search(start,end, what,e, boost::match_default)) { cout << what[0] << "\n"; } ______________________________________ Scanned and protected by Email scanner

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Problem in calculating cycle sequence...
by abhishek.v＠tcs.com 01 Oct '07

01 Oct '07

Hi I m able to calculate whether the cycle exist in the graph or not. With the help of following code.. //Finding out cycles struct cycle_detector : public dfs_visitor<> { cycle_detector( bool& has_cycle, int& num):_has_cycle(has_cycle),cycle(num) { } template <class Edge, class Graph> void back_edge(Edge, Graph&) { cycle++; _has_cycle = true; } protected: bool& _has_cycle; int& cycle; }; int main () { ...... .... .... //Finding out whether the graph has cycles.. bool has_cycle = false; int count_cycle=0; typedef Traits::vertices_size_type size_type; cycle_detector vis(has_cycle,count_cycle); boost::depth_first_search(g, visitor(vis)); if(has_cycle) { file_op << "\nThe graph is cyclic"<< std::endl; file_op<<"\nNumber of cycles in the graph is "<<count_cycle; } else std::cout << "The graph is acyclic"<< std::endl; return 0; } Now what i want is to calculate the vertex between which the cycle exist ... How to calculate that.. Thanks Abhishek Vyas Tata Consultancy Services Mailto: abhishek.v(a)tcs.com Website: http://www.tcs.com ____________________________________________ Experience certainty. IT Services Business Solutions Outsourcing ____________________________________________ =====-----=====-----===== Notice: The information contained in this e-mail message and/or attachments to it may contain confidential or privileged information. If you are not the intended recipient, any dissemination, use, review, distribution, printing or copying of the information contained in this e-mail message and/or attachments to it are strictly prohibited. If you have received this communication in error, please notify us by reply e-mail or telephone and immediately and permanently delete the message and any attachments. Thank you

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string_algo no replace_if
by gast128 01 Oct '07

01 Oct '07

Dear all I was requesting an 'erase_if' a while ago, and now I ran into a 'replace_if' problem. So after spendig 2 hours in the documentation, I finally found on www ('[string_algo] replace repeated char with single instance?') that one should use the 'find_format_all': boost::find_format_all(str, boost::token_finder(boost::is_any_of("ab")), boost::const_formatter("c")); But wouldn't it be better to make a 'replace_if' shortcut solely for the purpose of documentation reasons: boost::replace_all_if(str, boost::is_any_of("ab"), "c"); I think that most people find the last line easier to read and comprehend than its (more powerful) 'find_format' cousin. The string_algo library is nice but I get lost more than once. Especially find, replace, erease with predicates are often used by us. However direct use seems not possible. wkr, me

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Passing extra compiler arguments with bjam
by Cory Nelson 01 Oct '07

01 Oct '07

I'm wanting to pass some extra arguments for VC++ whole program optimization (specifically, /GL to the compile, /LTCG to the linker). Does anyone know how? -- Cory Nelson

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Problem in calculating critical path and fundamental ckts
by abhishek.v＠tcs.com 01 Oct '07

01 Oct '07

Hi.. I want to calculate the critical paths of a graph using BGL. So what i did is i calculated the connected components of a graph then remove the edge one by one if the number of connected component increase then the edge is critical edge or a bridge. This works fine in case of undirected graph. But how do i calculate connected component of a directed or Bidirected graph i m able to calculate the strongly connected component but it is not helping me out. Can you suggest me something regarding this. Also i want to calculate the fundamental ckt that exist in a graph now. What i did here is i m calculating K-MST. Now i want to calculate the fundamental ckt how should i do that... Thanks Abhishek Vyas Tata Consultancy Services Mailto: abhishek.v(a)tcs.com Website: http://www.tcs.com ____________________________________________ Experience certainty. IT Services Business Solutions Outsourcing ____________________________________________ =====-----=====-----===== Notice: The information contained in this e-mail message and/or attachments to it may contain confidential or privileged information. If you are not the intended recipient, any dissemination, use, review, distribution, printing or copying of the information contained in this e-mail message and/or attachments to it are strictly prohibited. If you have received this communication in error, please notify us by reply e-mail or telephone and immediately and permanently delete the message and any attachments. Thank you

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Inquiring about the feasibility of boost::mpl based statechart DSELs that generate boost::statechart based components
by Tony Turner 01 Oct '07

01 Oct '07

Greetings; I am currently experimenting with the feasibility of writing a boost::mpl based library of metaprograms that process statechart DSEL language phrases ( see ref #1 below), that then specifically generate boost::statechart based components. I would be most grateful to hear from others regarding both difficulties to this approach, as well as success stories. If this approach seems feasible, I would like to contribute the resultant code back to the open source community. Since I'm not sure how the contribution process works, I would appreciate it if someone could point me in the right direction. Reference (#1) ( the statechart developed in chap 11, "A DSEL Design Walkthrough" in Abrahams and Gurtovoy's "C++ Template Metaprogramming book".) Thankyou very much for your time; Tony Turner R&D Software Engineer

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