February 2011 - Boost-users - lists.preview.boost.org

[Boost Graph Library] larger neighborhood in grid_graph
by Hannes Schulz 03 Feb '11

03 Feb '11

Hi all, i recently discovered grid_graph and found it quite useful so far. However, I would prefer a larger neighborhood in the graph (e.g. 8 instead of 4 for 2D; 26 instead of 6 in 3D). I already started looking into copying and modifying grid_graph.hpp accordingly, but cannot entirely anticipate the complexity of the problem. Therefore I decided to ask here first: - Why did the developers restrict grid_graph to "orthogonal" neighborhoods? - Is a modification of grid_graph worth it, or am I going to throw away everything anyway and should start over anew instead? (without the wrapping overhead, which I do not need) Thank you very much! Hannes

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[Regex] Boost.Regex - can't compile/link...
by Robert Pennington 02 Feb '11

02 Feb '11

Hey there, I am trying to compile a very simple example program that I copied from the boost getting started guide for windows (after successfully running a bjam complete build). BTW: I am using the gcc compiler within the Code::Blocks IDE on Windows XP. Here is the code, just in case: ========================================================== #include <boost/regex.hpp> #include <iostream> #include <string> int main() { std::string line; boost::regex pat( "^Subject: (Re: |Aw: )*(.*)" ); while (std::cin) { std::getline(std::cin, line); boost::smatch matches; if (boost::regex_match(line, matches, pat)) std::cout << matches[2] << std::endl; } } ========================================================== Every time I try to compile this code (by hitting the 'Build and Run' button in Code::Blocks), I get a whole bunch of error messages. The first one I get is: "C:\Program Files\boost\boost_1_45_0\boost\regex\v4\cpp_regex_traits.hpp|366|undefined reference to `boost::re_detail::cpp_regex_traits_char_layer<char>::init()'|". Any ideas? Thanks in advance, Rob Pennington

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Fusion: Structs containing an array
by Gunther Laure 02 Feb '11

02 Feb '11

Hi! I am trying to use boost fusion to build [de]serializer for simple types (int ...) and structs. I had success until I tried structures holding arrays. Example: struct EntryTable { unsigned int count; unsigned int data[4]; }; BOOST_FUSION_ADAPT_STRUCT( EntryTable, (unsigned int, count) (unsigned int, data[4]) ) I would wish to get a fusion::vector<unsigned int, unsigned int[4]>, but the assignment of the struct only compiles if the fusion vector is defined as fusion::vector<unsigned int, unsigned int>. EntryTable t; fusion::vector<unsigned int, unsigned int> f1 = t; // works fusion::vector<unsigned int, unsigned int[4]> f2 = t; // doesnt work (not even compile) What am I doing wrong? Is there a simple way to simple wrap an array using fusion? Bye Gunther using boost 1.42 g++ 4.4.5

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Re: [Boost-users] Compiling Boost (Steven Watanabe, Bhushan Inamdar)
by Bhushan Inamdar 02 Feb '11

02 Feb '11

Hi Steven, Thanks for the prompt reply. My problem is solved. It seems that, every time, I have to go to project properties and in the C++ tab and include the absolute path to the Boost directory. After doing this, the program compiles with out any complaints. So further up, my question is...Is it necessary to do this everytime? Or my Boost installation is missing something? Let me know.... Thanks, Bhushan

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What's happened to Ryppl?
by Robert Jones 02 Feb '11

02 Feb '11

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Need help identifying present and past Boost authors
by John Wiegley 01 Feb '11

01 Feb '11

Hello, I'm working on a repository convertor which must translate SVN author ids to fullname/e-mail pairs. This has already been done to some extent by Brad King, but I've found that several authors remain unidentified. I'm sending this e-mail to ask the Boost community if they could identify any or all of the authors at the following URL whose name is Unknown. Also, if you can provide spelling corrections or more updated e-mail information, please let me know by e-mail. The current authors file is here: https://github.com/jwiegley/subconvert/blob/master/doc/authors.txt I'll update the file as corrections are provided. Thank you, John Wiegley BoostPro Computing http://www.boostpro.com

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[1.46.0 beta 1] [SourceForge] SourceForge mirror sync system broken
by Beman Dawes 01 Feb '11

01 Feb '11

The SourceForge mirror sync system has broken down. Other projects are affected, not just Boost. The files up there are probably good and the download problems should clear once the mirrors are synced again, the S/F folks say. Some projects say their files are back online, but as of a few minutes ago the Boost stuff still seemed broken and/or running so slowly as to be effectively broken. --Beman

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[boost.test] benchmarking support
by Marco Craveiro 01 Feb '11

01 Feb '11

hi boosters, i've been looking for benchmarking support for unit tests, but googling didn't produce any obvious results (and a wealth of spurious matches, so i may have missed something). what i have in mind is something akin to cppbench but for boost.test: http://blog.quibb.org/cppbench/ basically, something that allows repeating each test a number of times, and then time the total execution time per test. is this available? if not, can anyone recall any discussions on the subject? many thanks for your time, marco -- Constraint has encouraged not only economy, but also a certain elegance of design. -- Dennis Ritchie

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[Review][Move] Boost.Move Review Results
by Michael Caisse 01 Feb '11

01 Feb '11

---------------------------- Executive Summary ---------------------------- Ion Gaztañagas' Boost.Move library was reviewed from May 10th, 2010 through May 24th, 2010. The original review manager was OvermindDL1 who later went missing. Eleven individuals joined the discussion with the author. Six reviews were submitted: - 5 reviews ACCEPT - 1 review CONDITIONALLY ACCEPT Ion indicated he would meet the "conditional requirements" which easily satisfies a community vote of: Boost.Move library ACCEPTED ---------------------------- Overview ---------------------------- The Boost.Move library is a highly anticipated addition to the Boost collection. The primary motivation is to introduce usable move functionality in "a portable syntax between C++0x and C++03 compilers"; however, as Vicente Botet articulated, "Most people think that this is an emulation library, but it is more than that as it implements most of the C++0x Move semantics classes and functions." Reviewers' comments: - "This library is long overdue!" [Terry Golubiewski] - "The tutorial is well written." [Vicente Botet] - "Compared to my adobe based move implementation, I think yours is superior." [Daniel James] - "There is a lot of ingenuity in making the move emulation work, and Ion has made it very accessible and managed to make differences between C++03 and C++0x vanish behind macros and free functions." [Jeff Hellrung] An active discussion included: - exposing boost::rv<T> publicly - The merits of fully defining requirements of boost::rv<T>& - Duplicated functionality found in MPL and Type Traits - The necessity for two emulation modes - The merits of macros - Library author usage of Boost.Move - Non-throwing move constructors - Various potentially useful type traits - Other move implementations While it is unfortunate that a timely review result was not published, it did provide an opportunity to discuss some of the concerns raised in the review with actual users of the library. One such concern was the "two emulation modes." At some point in the discussions it became classified as "Safe vs. Fast". When coined with that bias "safe" would be the preference; however, further investigation and inquiries of actual users showed the "fast" version is perfectly acceptable as the default. Additionally, "safe" is a misnomer considering that one mode is not any safer than the other. Each mode has benefits and limitations as enumerated by Ion in the documentation and review responses. The past six months of use would indicate that defaulting to the "fast" version, as preferred by Ion, is in practice a good decision. Thank you Ion for this well thought out and excellent submittal. Thank you reviewers for expending time and energy to further Boost. Without those who are dedicated to review submitted libraries, the entire process and Boost itself falls apart. The community will benefit from the effort each of you put into this library. Best regards - Michael Caisse ---------------------------- Summary of changes ---------------------------- The following changes are planned based on discussions from the review: -- Conditional Acceptance -- 1. "Two Emulation Mode" documentation typos must be resolved. The descriptions, requirements and limitations need to be perfectly clear for the end user. -- Other Issues -- 1. The class rv should be public and documented. 2. is_movable should be renamed and the documentation clarified. It should only be enabled in C++03. A possible alternative name is has_move_emulation_enabled. 3. Nearly all reviewers voiced a preference that the move library should use existing functionality from MPL and TypeTraits libraries. While on one hand this creates a dependency between move and other libraries it results in reuse of accepted and well tested libraries. If a non-coupling option is also provided, it should not be the default. 4. Additional traits discussed. Resolution: add to TypeTraits library as actual use-cases are found. 5. Provide a boost/move.hpp that includes boost/move/move.hpp 6. Document the interaction of the two emulation modes. 7. Include example for making a container "movable". 8. Two emulation modes - Ion was hopeful that reviewers would have a uniform opinion that would result in a single mode. The trade-offs identified by Ion in the documentation were apparent to all reviewers; however, different conclusions were drawn and consensus was not met. The granularity of control was a common issue with nearly all reviewers. Therefore, keep both emulation modes with Optimized as the default and the granularity of control at or more "local level" than the macro provides (class level). 9. emulation_limitations.html: s/overaloading/overloading/ 10. Fully qualify enable_if ( ::boost::emable_if ) 11. Optimized version of forward should use identity so it will not try to deduce T. 12. Make sure required headers are mentioned for tutorials. 13. is_class in is_movable template< class T> struct is_movable : mpl::and_< is_class<T>, mpl::not_< is_rvalue_reference<T> >, is_convertible< T, rv<T>& > > {}; - or - another solution to is_movable problems with references. 14. On throwing move constructors, Ion should follow as close to the standard's behaviour as possible. This can be revisited after the initial release since it is a performance optimization. -- Michael Caisse Object Modeling Designs www.objectmodelingdesigns.com

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win32 api
by Gianni Ambrosio 01 Feb '11

01 Feb '11

Hi All, I'm working on a piece of code that should run on a special real-time kernel that supports only a minimal set of win32 api. I would like to use boost sockets and threads but it seems there are some dependencies on win32 api not supported by that system (i.e. WSARecvFrom, WSASend, WSASocketA, WSAStringToAddressA). Is there a way to build boost libs with some options so that the C socket calls are used instead? I'm asking too much? Regards Gianni

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