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[utility/value_init] boost::value_initialized<T> direct-initialized?
by Niels Dekker - address until 2010-10-10 09 Apr '10

09 Apr '10

Can anybody please have a look at the following feature request by Edward Diener? https://svn.boost.org/trac/boost/ticket/3472 He proposed to add an explicit constructor, value_initialized(T const&), to boost::value_initialized<T>. This constructor would copy the value of its argument to the object held by value_initialized<T>. When such a constructor would be added, an object held by value_initialized<T> might no longer be value-initialized. Instead it might be direct-initialized. Does anybody have any moral (?) objections against the idea that value_initialized<T> might hold a non-value-initialized object? Personally I think it would be useful to allow the wrapped object to be direct-initialized. But I do think there's a small risk that the new explicit constructor might cause ambiguities in legacy user code. Therefor I suggested adding an extra "tag" parameter to the new constructor, of a new type, boost::direct_initialized_t: struct direct_initialized_t { }; value_initialized(T const&, direct_initialized_t) Does anyone else also think that's a good idea? Or does anyone prefer the explicit value_initialized(T const&) constructor originally proposed by Edward? See also the thread starting at: "Re: [boost] Transfer of Maintenance Rights (utility/value_init)" http://lists.boost.org/Archives/boost/2010/03/164125.php Kind regards, Niels -- Niels Dekker http://www.xs4all.nl/~nd/dekkerware Scientific programmer at LKEB, Leiden University Medical Center

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xml?
by Maarten L. Hekkelman 09 Apr '10

09 Apr '10

Hi, I saw there was some discussion on this list regarding an XML library. I wrote a C++ based XML library recently as part of the work I do on e.g. MRS, a full-text retrieval system for biological databanks. (See http://mrs.cmbi.ru.nl/ ) I extracted the XML and SOAP code from the MRS project and wrapped it into a new library. This library is called libzeep and I've put the code on Berlios (http://libzeep.berlios.de/) License is Boost. The library currently consists of: - a SAX parser with validation support based on DTD. - a simple XML library for nodes, elements, etc. - an XML writing utility/wrapper. - an xpath implementation And then the code contains a full high-performance SOAP server implementation. This code generated all SOAP related code and WSDL generator code based on the signature of exported server methods. No need to run a separate code generating tool. Network code is based on asio and I've implemented an optional pre-forked mode of operation. A previous version of libzeep is in production use for over a year now and I recently added the parser and xpath stuff to be able to drop libxml2 from the requirements for MRS. Code comes with quite a few test sets. Documentation is not updated yet for the parser and xpath but there is some for the SOAP part. I need to do a bit more testing before I can release a new version. My question now is, would this library be of interest to Boost? Perhaps it can be used, or parts of it can be recycled. And if there is interest, I'm sure there must be suggestions for improvement. You can browse the code at https://svn.cmbi.ru.nl/libzeep/trunk/ (There's also a copy at Berlios, but that may be out-of-date) The application zeep-test is a simple SOAP server, in ./tests/ you can find two simple test drivers, one for the parser and one for xpaths. Best regards, -maarten hekkelman

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[GSoC] Students; Please note..
by Rene Rivera 09 Apr '10

09 Apr '10

GSoC students, Now that the GSoC submission deadline has passed it is vitally important that you pay attention to your proposals and the comments the mentors add to them. Please address questions and suggestions we put on the comments ASAP. As it will both make our lives easier, and hence more likely to make accurate assesments of proposals. And it will increase the chances that we consider your proposals serious enough to want to move forward, if we get our feedback resolved. Good luck to all :-) -- -- Grafik - Don't Assume Anything -- Redshift Software, Inc. - http://redshift-software.com -- rrivera/acm.org (msn) - grafik/redshift-software.com -- 102708583/icq - grafikrobot/aim,yahoo,skype,efnet,gmail

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[config] New defect macro: BOOST_NO_COMPLETE_VALUE_INITIALIZATION
by Niels Dekker - address until 2010-10-10 09 Apr '10

09 Apr '10

FYI, John Maddock has just added the tests to trunk/libs/config that I wrote for a new defect macro: BOOST_NO_COMPLETE_VALUE_INITIALIZATION https://svn.boost.org/trac/boost/changeset/61153 And some documentation: https://svn.boost.org/trac/boost/changeset/61154 A test failure indicates that the specific compiler doesn't have completely implemented value-initialization. In the coming few days, the test is likely to cause regression failures, because I still need to define the defect macro for those specific compilers (at boost/config/compiler). Although I already expect certain compilers to fail (MSVC <= 2010, CodeGear/Borland <= 2010, GCC < 4.4, and various versions of Sun) I chose not to define the defect macro /beforehand/, because the test output provides some extra information about the particular compiler issue. Moreover, once the defect macro is defined, the test framework no longer indicates whether the compiler defect is really there. I'll keep an eye on the regression page, http://www.boost.org/development/tests/trunk/developer/config_.html and fix them one by one, but please don't hesitate to remind me if there's a regression failure regarding the new defect macro that I overlooked. The defect macro will allow fixing ticket #3869, "Unconditional call to memset in value_initialized()", reported by Aleksey Gurtovoy: https://svn.boost.org/trac/boost/ticket/3869 by adding an #ifdef to utility/value_init.hpp: #ifdef BOOST_NO_COMPLETE_VALUE_INITIALIZATION std::memset(&x, 0, sizeof(x)); #endif Kind regards, Niels -- Niels Dekker http://www.xs4all.nl/~nd/dekkerware Scientific programmer at LKEB, Leiden University Medical Center

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Re: [boost] [msm] new version available
by Christophe Henry 09 Apr '10

09 Apr '10

> The new package on Vault is missing boost/msm/back/default_compile_policy.hpp. > Everything seems to compile fine once I grabbed it from the sandbox, so I assume > the other files in the package are the proper versions. I found the problem. SVN refuses to correctly update the directory I used to build the zip. Even cleanup has no effect, so I will delete the whole stuff and checkout again. There are actually 2 important files missing, so I had no other choice than to upload the correct version again. For all who downloaded from the vault, sorry about it, you will need to download again (the sandbox is ok though). > Also, I very much dislike that metafunctions.hpp does 'namespace mpl = > boost::mpl;' in global scope. Isn't putting anything in global scope against the > boost guidelines? Even if not, I find it quite inappropriate to inject another > library's namespace into global scope. This line is not even needed as all mpl types are qualified inside the library with ::boost::mpl so I just removed the line. This problem is there since at least the 1.20 and went unnoticed. Sadly, some of the tutorials fail to fully qualify the mpl types, so I updated them too. Both versions, sandbox and vault should now be up to date and with these 2 problems solved. Thanks, Christophe

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GSoC 2010: Heaps and Queues
by Dan Larkin 09 Apr '10

09 Apr '10

I'm another potential student throwing my hat in the ring for the heap project. I'll save most of my personal details for my proposal, but for right now I thought I'd try to get a bit of a dialogue going with the community to help me understand what it is you guys are looking for and what it is I can work towards. So I'll start with my current understanding of the situation. The way I see it, the current heap implementations in boost/pending are rather fractured. They just have simple push/pop interfaces with no mutability (well, there's mutable_heap.hpp, but that's separate and not fleshed out). All in all, what seems to be needed is a standardized heap concept/API along with a few fully-implemented models. Standard heap functionality begs the following functions: - findMin - deleteMin - insert - changeKey - merge These can all be implemented quite efficiently (either worst case or amortized O(logn) time or better) for any heap model. I would be looking to implement the d-ary, binomial, and Fibonacci heaps for sure, with relaxed and Brodal heaps as a possibility, should time allow it. These heap models would be built as extensions of a base Heap class, which could be easily wrapped in a PriorityQueue class which takes the heap-type as a construction parameter (and defaults to a d-ary heap for instance). I know that a stable priority queue was mentioned in earlier discussion, but I'm not sure what to do about that just yet. It'll take a little more thinking before I could say whether I think it'd fall under the scope of the summer project, or if it should be put on the back-burner for later addition to the library. I guess that's basically how I see the problem so far. Please let me know what you think, or what other sort of information/planning/etc. you would like to hear from me prior to my proposal/draft. Dan Larkin

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Boost.Botan final proposal
by Chad Seibert 09 Apr '10

09 Apr '10

Hi, Pending any other revisions, here's my final proposal: http://socghop.appspot.com/gsoc/student_proposal/edit/google/gsoc2010/chads… Thanks to all who gave advice, please ask if you have any questions! Chad Seibert _________________________________________________________________ Hotmail is redefining busy with tools for the New Busy. Get more from your inbox. http://www.windowslive.com/campaign/thenewbusy?ocid=PID28326::T:WLMTAGL:ON:…

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[GSoC] Bits & Ints proposal
by Murilo Adriano Vasconcelos 09 Apr '10

09 Apr '10

Here is my proposal for Bits & Ints idea: http://socghop.appspot.com/gsoc/student_proposal/show/google/gsoc2010/muril… Any comments? -- Murilo Adriano Vasconcelos

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boost::interprocess
by Rohit Goel 09 Apr '10

09 Apr '10

Hi, How can I synchronize mutlipe read/single write on a file available on a shared folder ? The multiple read/write need to be synchronized b/w different processes running on different machine. -Rohit

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[msm] new version available
by Christophe Henry 09 Apr '10

09 Apr '10

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 - some performance gain - new eUML syntax to get rid of parens and to better support attributes - policy for better compile-time at cost of dispatch speed. And a few minor improvements. It was not possible to implement every wish and excellent idea offered during the review at this point, but they are in no way forgotten and I do not intend to stop development now. I'm interested in any comments, especially about the doc, which, like everything new, probably is not perfect but I hope, still an improvement. You can find the new version, like always: - in the Vault (http://www.boostpro.com/vault/index.php?directory=Msm) - in the sandbox (http://svn.boost.org/svn/boost/sandbox/msm/) Regards, Christophe

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