October 2010 - Boost - lists.preview.boost.org

[review result] mini-review of update to Boost.Assign
by Thorsten Ottosen 18 Oct '10

18 Oct '10

Dear all, Here follows the result of the result of Erwann Rogard's update to Boost.Assign: **************************** The update is not accepted **************************** This is not because the new functioanlity/interface was not seen as an improvement, but because Erwann has chosen to implement a full replacement (or Assign v2) based on the feedback he got during the review. The feedback meant that the new "update" would be much larger than what was present in the mini-review, and the new library should therefore be subject of its own full review. I would like to thank Erwann for his hard work so far, and hope he submits a Boost.Assign v2 in the near future. I would also like to thank the following people who participated in the mini-review: Christopher Jefferson Diederick C. Niehorster John Bytheway kind regards Thorsten, review manager

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[pool] detail/mutex.hpp may include windows.h and pollute namespace with windows definitions.
by Paul Blampspied 18 Oct '10

18 Oct '10

I have been making an effort to write Windows independent code. In particular I avoid including windows.h in any of my headers (some implementation files include it). I have had a problem using Boost/pool as the mutex header includes windows.h (causing nameclashes with some of my existing code, which has always relied on the absence of windows.h). Possible inclusion of windows.h is documented in the section on mutex. My question is 'Is it really necessary or desirable ?'. Is there a Boost policy on the inclusion of OS specific headers which create a large number of declarations in the global namespace ? The section which uses windows.h is: #ifdef BOOST_WINDOWS class win32_mutex { private: ::CRITICAL_SECTION mtx; win32_mutex(const win32_mutex &); void operator=(const win32_mutex &); public: win32_mutex() { ::InitializeCriticalSection(&mtx); } ~win32_mutex() { ::DeleteCriticalSection(&mtx); } void lock() { ::EnterCriticalSection(&mtx); } void unlock() { ::LeaveCriticalSection(&mtx); } }; #endif // defined(BOOST_WINDOWS) I believe that the appropriate declarations of InitializeCriticalSection, DeleteCriticalSection, EnterCriticalSection, LeaveCriticalSection could be provided explicitly in this file and hence avoid including windows.h and the subsequent namespace 'pollution'. An alternative of using a Boost multithreading library is suggested in the documentation. This would be ideal, but my proposal would solve problem now, relatively effortlessly. PS. I did a quick edit and got it to work (at least on Vista). The change to the if-endif block is shown below. It could be done much better. # ifdef BOOST_WINDOWS //#include <windows.h> typedef char CRITICAL_SECTION[24]; //24 is sizeof(CRITICAL_SECTION) ! typedef CRITICAL_SECTION *LPCRITICAL_SECTION; #define WINAPI __stdcall extern void WINAPI InitializeCriticalSection( __out LPCRITICAL_SECTION lpCriticalSection ); extern void WINAPI DeleteCriticalSection( __inout LPCRITICAL_SECTION lpCriticalSection ); extern void WINAPI EnterCriticalSection( __inout LPCRITICAL_SECTION lpCriticalSection ); extern void WINAPI EnterCriticalSection( __inout LPCRITICAL_SECTION lpCriticalSection ); void WINAPI LeaveCriticalSection( __inout LPCRITICAL_SECTION lpCriticalSection ); # endif many regards, Paul

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[property_tree] Copy constructor and assignment operator in xml_writer_settings class
by Mateusz Loskot 18 Oct '10

18 Oct '10

Hi, What is recommended or required policy regarding copy operations for types which consist of const data members, within Boost? I'm having problem with understanding why the xml_writer_settings class do not have the copying operations disabled. Perhaps it should be patched? Quick chat on the #boost IRC channel confirms it could be improved. I'm looking forward comments. [1] https://svn.boost.org/trac/boost/browser/trunk/boost/property_tree/detail/x… Best regards, -- Mateusz Loskot, http://mateusz.loskot.net Charter Member of OSGeo, http://osgeo.org Member of ACCU, http://accu.org

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is_convertible_basic_impl and OpenMP - compile error
by Remi 18 Oct '10

18 Oct '10

Hi, I'd like to report nasty behaviour of boost when used inside OpenMP loops. In the following example compile error is generated under Visual 2008, if "default(none)" is used for OpenMP variable data sharing attribute clauses (which is the recommended choice). #define BOOST_ALL_NO_LIB 1 #include <boost/graph/adjacency_list.hpp> #include <omp.h> int main(int argc, char* argv[]) { typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS> GraphType; typedef GraphType::adjacency_iterator GraphAdjacencyIterator; const unsigned int vertex_count( 20 ); typedef std::pair<int, int> EdgeType; std::vector<EdgeType> edges; const GraphType graph( edges.begin(), edges.end(), vertex_count, edges.size() ); int i( 0 ); #pragma omp parallel for schedule(static, 1) default(none) private(i) shared(vertex_count, graph) for ( i = 0; i < vertex_count; ++i ) { const std::pair<GraphAdjacencyIterator, GraphAdjacencyIterator> adjacent ( boost::adjacent_vertices(i, graph) ); } return 0; } "\boost\boost/type_traits/is_convertible.hpp(263) : error C3052: '_m_from' : variable doesn't appear in a data-sharing clause under a default(none) clause"

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Version information for Boost library
by Edward Diener 18 Oct '10

18 Oct '10

Does Boost have any policy regarding the way version information should be attached to a library ?

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Does boost support ccache?
by Alexander Churanov 18 Oct '10

18 Oct '10

Folks, I've encountered an issue: boost libraries fail to build under ccache. The questions are: 1) Are boost libraries and ccache compatible? 2) If not, should I file a new bug? One of users contacted me and reported failure to build boost libraries version 1.43 on FreeBSD 7.3 (GCC 4.2.1). There were, however, no failures on the FreeBSD ports build cluster. Quick comparison of logs revealed that build cluster does not use ccache - compilation cache tool for C++ and other languages. Removing ccache from the toolchain fixed the issue, so it is an acceptable workaround. The logs are available here: http://alexanderchuranov.com/boost-issues/ccahe-freebsd-7-boost-1.43/ The original filed issue is here: http://www.freebsd.org/cgi/query-pr.cgi?pr=ports/151454 The patches for boost-libs port are here: http://www.freebsd.org/cgi/cvsweb.cgi/ports/devel/boost-libs/files/ Alexander Churanov, maintainer of devel/boost-* ports for FreeBSD

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Question about commercial software and boost license
by marc_elias＠terra.es 18 Oct '10

18 Oct '10

Hi, I'm working in a company that want to use boost libraries to a commercial software. I have a pair of questions: 1. Is it possible to distribute under the boost license a commercial software (so the source code won't be exposed) programmed with static boost libraries? 2. And with linked libraries to an executable? Thanks in advance! MARC

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[1.45] Release notes
by Daniel James 18 Oct '10

18 Oct '10

Hello all, Once more, it's time to prepare the release notes. If you want to add to them yourself, you can edit the source files in subversion here: http://svn.boost.org/svn/boost/website/public_html/beta/feed/history/ Or if you prefer, you can email me the details and I'll add it for you. Because the relevant web pages are now served as static files rather than as dynamic php pages, rebuilding the feeds won't change the web site. The process for generating the pages was a quick hack and is pretty horrible, so it's probably best if you leave that to me for this release. I'm writing a new python script to do all of this (the only requirement will be a quickbook executable), so hopefully it'll be a lot easier next time. Daniel

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[network] cpp-netlib 0.7 ready to be released
by Dean Michael Berris 18 Oct '10

18 Oct '10

Hi Guys, I just wanted to give everyone interested a heads up on the progress being made on the cpp-netlib project (which I'm working on full-time at the moment). Basically: * There's now an asynchronous/active HTTP client implementation that returns response objects that encapsulate futures. This uses the Boost.Asio asynchronous socket interfaces to implement reads/writes on the active object. * The documentation has been moved from Quickbook to ReStructuredText and generated with Sphinx (and they look really nice if I may say so myself: http://mikhailberis.github.com/cpp-netlib/) * The message concept has been fleshed out and now requires external modifiers. * Requirement for OpenSSL has been dropped, now by default doesn't support HTTPS unless specified. This impending 0.7 release also uses more template metaprogramming tools from Boost.MPL to implement the tag dispatch mechanism to modify behaviors of the classes based on these tags. Policies were introduced and are chosen depending on the characteristics of the tags provided. Development on 0.8 shall include: * A more feature-complete HTTP server template that supports a worker thread pool where handlers get invoked, and where handlers can write data to the connection asynchronously. * A streaming HTTP client interface to support passing a raw stream associated with a socket to a handler function or as part of the response object returned. * A preliminary XMPP client implementation. * The beginnings of a web service framework on top of the HTTP server to allow for a more web-framework like feel, similar to how web frameworks like Tornado Web (http://tornadoweb.org/) Target release of 0.8 will be the first week of November. The development of cpp-netlib targets an end-of-year submission to the Boost Library, and hopefully those interested in the project can go ahead and try it out now so that I and the other developers can work on feature requests before that time -- and so that early evaluations can guide the direction of the development before December. Thanks everyone and I look forward to hearing from you! Note: You can find the documentation for cpp-netlib (which I presented at BoostCon 2010) at http://mikhailberis.github.com/cpp-netlib -- Dean Michael Berris deanberris.com

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boost.foreach overhead
by Christopher Lux 18 Oct '10

18 Oct '10

On 10/9/2010 John Carmack of id Software wrote on his Twitter account: “@ID_AA_Carmack: It took 69 single steps to get past a BOOST_FOREACH() statement. Madness.” This made me think again about the overhead introduced with boost foreach. Is the overhead really this large as he makes it sound? Are there heuristics to when to use foreach according to the expected iteration counts? Regards -chris -- Christopher Lux | | Bauhaus-Universität Weimar | Faculty of Media - Virtual Reality Systems Group | Tel. +49 (0) 3643 - 58 3734

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