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

18 Oct '10

Hi Everyone! So, I've been busy the past few hours doing a final push to get 0.7 out the door so that starting tomorrow I can start working on the 0.8 branch to improve the server-side HTTP implementation. Now, it's official, 0.7 is out the door and is ready for prime-time. ;-) In case you'd like to try it out, it's header only and you can download the 0.7 release from: http://github.com/cpp-netlib/cpp-netlib/downloads This has numerous improvements and enhancements over the 0.6 version, and has a more robust definition of the concepts included in the library. Now anybody can start extending cpp-netlib with their own protocol implementations using the common message type. If you want your work to integrate cleanly with the project, you can go ahead and fork my repository (as the project's "benevolent dictator for life") and submit pull requests in case you want to get your implementation/fixes/extensions into the main library distribution. As earlier stated, 0.8 will be a server-side focused development effort which will include a lot of cool things not just an improved HTTP server interface. If you'd like to discuss the effort or join the development, please feel free to send email to either the Boost Developer mailing list (because this library will be submitted for review and inclusion in Boost around December 2010) or the cpp-netlib developers mailing list. Thanks to everyone who's expressed interest, and those who have offered suggestions on the improvements to be made to the library. I hope everyone had a great weekend too! -- Dean Michael Berris deanberris.com

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[OT] Calling Overmind
by John Phillips 18 Oct '10

18 Oct '10

Overmind, Would you please either contact me (John Phillips), or Ron Garcia off list? Thanks. John

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3rd- party reliance for upcoming boost.GIL.IO library
by Christian Henning 17 Oct '10

17 Oct '10

Hi there, We are going to submit the Boost.GIL.IO extension for review and the package relies on 3rd-party libraries; can anyone suggest minimum solution for finding those libraries which would be usable for reviewers to build and run tests/examples? The library is pretty much ready for review and can be found here: http://gil-contributions.googlecode.com/files/boost_review.zip or via SVN, here: http://code.google.com/p/gil-contributions/source/browse/#svn/trunk/gil_2 Thanks, Christian

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[unordered] error: template argument required for ‘struct set_extractor’
by Mateusz Loskot 17 Oct '10

17 Oct '10

Hi, I'm experiencing strange problem with unordered_map.hpp file. I'm using Boost 1.44 with GCC 4.2.1 from XCode on Mac OS X. Compiling simple test: $ cat foo.cpp #include <boost/unordered_map.hpp> int main() {} $ g++ -o foo.o foo.cpp In file included from /usr/local/include/boost/unordered/detail/equivalent.hpp:11, from /usr/local/include/boost/unordered/unordered_map.hpp:19, from /usr/local/include/boost/unordered_map.hpp:16, from foo.cpp:1: /usr/local/include/boost/unordered/detail/extract_key.hpp:31: error: template argument required for ‘struct set_extractor’ /usr/local/include/boost/unordered/detail/extract_key.hpp:77: error: template argument required for ‘struct map_extractor’ I've looked at the preprocessed file and there is something that disturbs me - templates of set_extractor and map_extractor are getting "changed". Comparing preprocessed file against source from boost/unordered/detail/extract_key.hpp I see 1) set_extractor a) original code template <class ValueType> struct set_extractor { typedef ValueType value_type; typedef ValueType key_type; b) preprocessed output struct set_extractor { template <class ValueType> struct apply { typedef ValueType value_type; typedef ValueType key_type; 2) map_extractor a) original code template <class Key, class ValueType> struct map_extractor { typedef ValueType value_type; typedef BOOST_DEDUCED_TYPENAME boost::remove_const<Key>::type key_type; b) preprocessed output struct map_extractor { template <class ValueType> struct apply { typedef ValueType value_type; typedef typename remove_const<typename ValueType::first_type>::type key_type; As you can see, the set_exctractor and map_exctractor templates have lost template parameters declarations and some extra nested struct has been generated: template <class ValueType> struct apply Folks on #boost at IRC suggested it may be caused by MPL magic. I haven't noticed any such problem with GCC 4.4 on Linux with Boost 1.43 There has been similar issue reported, but the problem was ALLOC macro defined by RICE library, what rather is not my case: http://lists.boost.org/boost-users/2010/05/59340.php Does anyone have an idea what's happening? 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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[CfP] 5th Annual BoostCon, Aspen (CO, USA), May 15-20, 2011
by Hartmut Kaiser 16 Oct '10

16 Oct '10

Please distribute. ------------------ 5TH ANNUAL BOOST CONFERENCE 2011 Aspen CO, USA, May 15 - 20, 2011, www.boostcon.com CALL FOR PARTICIPATION We invite you to submit session proposals to the 5th Annual Boost Conference: BoostCon 2011 (Aspen CO, USA, May 15 - 20, 2011). Traditionally the main face-to-face event for all things Boost (www.boost.org) BoostCon 2011 will present leading speakers from the whole C++ community. >From using the Boost libraries to writing and maintaining them, from evangelizing to deploying Boost within your organization, from infrastructure and process to vision and mission, and the new C++ Standard, BoostCon brings together the sessions, the colleagues, and the inspiration to support your work with C++ and Boost in particular for the next year. To reflect the breadth of the Boost community, the conference includes sessions aimed at three constituencies: Boost end-users, hard-core Boost library and tool developers, and academics focusing on researcher. The program fosters interaction and engagement within and across those groups, with an emphasis on hands-on, participatory sessions. SESSION TOPICS Topics of interest include, but are not restricted to, the following: * General tutorial sessions introducing one or more Boost libraries * In-depth sessions on using specific Boost libraries * Case studies on using Boost * Experts panels * Advanced sessions on implementation techniques used within Boost libraries * C++0x and how it changes life for users and library writers * Development workshops to extend or enhance existing Boost libraries * Workshops on design process * Infrastructure workshops such as Build tools, Website, Testing * Concepts and Generic Programming * Hardware and infrastructure presentations focused on how libraries can make better use of the technology * Software development tools and their application to C++ and or Boost * Other topics likely to be of great interest to Boost users and developers Interactive and collaborative sessions are encouraged, as this is the nature of both the on-line Boost community and the style of learning and participation that has proven most successful at such events. Sessions can be tutorial based, with an emphasis on interaction and participant involvement, or workshop based, whether hands-on programming or paper-based, discussion-driven collaborative work. SESSION FORMATS Presentations ------------- Presentations focus on a practitioner's ideas and experience with anything relevant to Boost and Boost users. Panels ------------- Panels feature three or four people presenting their ideas and experiences relating to Boost's relevant, controversial, emerging, or unresolved issues. Panels may be conducted in several ways, such as comparative, analytic, or historic. Tutorials ------------- Tutorials are sessions at which instructors teach conference participants specific Boost-relevant skills. Workshops ------------- Workshops provide an active arena for advancements in Boost-relevant topics. Workshops provide the opportunity for experienced practitioners to develop new ideas about a topic of common interest and experience. Author's Corner Presentations These were introduced at BoostCon 2008, and were a great success. They are short (30 minute) sessions, focusing on tips on usage and design. In addition, we're looking to uncover the hidden design gems in Boost libraries. Tool Vendors Presentations We actively encourage tool vendors and ISP's to submit proposals for a special Tool Vendors Session Track aimed at products related to Boost and C++ (compilers, libraries, tools, etc.). Other formats may also be of interest. Don't hold back a proposal just because it doesn't fit into a pigeonhole. SUBMITTING A PROPOSAL Standard Sessions are 90 minutes. You may submit a proposal for fractions or multiples of 90-minutes. Fractional proposals will be grouped into 90 minute sessions covering related topics. Longer sessions, such as tutorials and classes, will be assigned 90 minute, three hour (i.e. half day), or six hour (i.e. full day) time slots. Please include: * The working title. * Type of session: presentation, panel, tutorial, workshop, authors corner, vendor track, other. * A paragraph or two describing the topic covered, suitable for the conference web site. * Proposed length: 10-20 minute short talks, 45 minutes, 90 minutes, half day, full day. * Alternate lengths, if you are willing to make adjustments: 10-20 minute short-talks, 45 minutes, 90 minutes, half-day, full day. * Audience: users, developers, both. * Level: basic, intermediate, advanced. * A biography, suitable for the conference web site. * Your contact information (will not be made public). SUBMISSION DETAILS All submissions have to be done through the EasyChair conference management system: http://www.easychair.org/conferences/?conf=boostcon2011. If you have not already registered at EasyChair, you will need to do so in order to submit your proposal. All submissions will go through a peer review process. Authors are invited (but are not required) to submit PDF versions of full papers of up to 10 pages in ACM conference proceedings format (see http://www.acm.org/sigs/publications/proceedings-templates) The full papers are not required unless you want them published in the proceedings. All accepted proposals will be made available in the Association for Computing Machinery (ACM) Digital Library (approval pending). Best papers, after further reviews, will be considered to be book chapters or journal articles in a renowned journal. The session materials go on the BoostCon website and will be available to attendees. For general information on the BoostCon 2011 paper submission or the scope of technical papers solicited, please refer to the conference website at www.boostcon.com. For any other questions about the submission process or paper format, please contact the Program Committee at boostcon2011(a)easychair.com. If you have any technical problems with EasyChair, please contact EasyChair for help. Note: Presenters must agree to grant a non-exclusive perpetual license to publish submitted materials, either electronically or in print, in any media related to BoostCon. IMPORTANT DATES Proposal submissions due: December 10th, 2011. Proposals decisions sent (tentative program available): January 17th, 2011. Fully scheduled program available: February 7th, 2011. Session materials due: April 15th, 2011. Hartmut Kaiser, email: hartmut.kaiser(a)gmail.com (Program Committee Chair) David Abrahams, email: dave(a)boostpro.com (Conference Chair) On behalf of the conference organizers

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[Pointer Container] Modification of pointer containers to allow const elements
by Gerardo Hernández 16 Oct '10

16 Oct '10

The following code snippet: boost::ptr_vector<const int> v; v.push_back(new int); produces the following error message (Visual C++ 9, boost 1.44): boost\ptr_container\ptr_sequence_adapter.hpp(249) : error C2664: 'std::vector<_Ty,_Ax>::push_back' : cannot convert parameter 1 from 'const int *' to 'void *const &' The problem is that the underlying type of boost::ptr_vector<T> is always vector<void*>, no matter T is const. This prevents push_back() method from maintaining const-correctness. The rest of the pointer containers contain an equivalent problem and this has been a TODO for some time. According to Thorsten Ottosen (library author) ( https://svn.boost.org/trac/boost/ticket/3832 ): "The fix is basically just some meta-functions taking into account that T might be const, and if so, instantiate container<const void*> instead of container<void*>" To the vector problem, this means that the underlying type should be: vector<typename boost::mpl::if_<boost::is_const<T>, const void*, void*> > I have sucessfully applied this approach to the pointer containers that mimic STL counterparts (see attachment) and I guess it should work for the others. I need feedback on whether this is a completely correct approach and if so I would like to contribute a modification. Gerardo.

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[optional] memory use for optional refs and ptrs
by Rutger ter Borg 15 Oct '10

15 Oct '10

Hello, I'm looking into boost::optional<> as a replacement for some of my code which has to deal with optional values. However, it seems that cases which are usually space-efficient optionals (e.g., ptrs in the form of a null-ptr) do not have template specializations. In other words, boost optional templates store a bool and the memory footprint of its template parameter, regardless of type. I.e., optional references and pointers take their space plus the space of an extra bool. Is there a reason for this? Thanks, Rutger

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New Boostcon sessions uploaded
by Marshall Clow 14 Oct '10

14 Oct '10

Michael Caisse: Using Spirit V2: Qi and Karma http://blip.tv/dashboard/episode/4162161 Stephan T. Lavavej: Data Structure Visualizers in Visual Studio 2010 http://blip.tv/dashboard/episode/4162044 Matt Calabrese, Zachary Laine: Instantiations Must Go! http://blip.tv/dashboard/episode/4161957 Jeremy Siek: Generic Programming And the Boost Graph Library http://blip.tv/dashboard/episode/4161923 More to come (I'm shooting for one session every other day)..... -- Marshall

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C++0x trailing return type
by Matt Calabrese 14 Oct '10

14 Oct '10

I'd like to introduce a macro to Boost.Config called BOOST_NO_TRAILING_RETURN_TYPE for checking if a compiler supports 0x trailing return types I.E. auto foo() -> void; Is there general agreement that this is an appropriate name for the macro? Now for a small rant -- in a recent thread, I talked about introducing a simple BOOST_AUTO_FUNCTION macro which I'll request review for shortly, as a way to simulate automatic return type deduction when writing functions and function templates. In experimenting with the macro, I have hit what I believe is either a bug in GCC or what I would consider a huge failing of C++0x trailing return types (someone please aid me in figuring this out). One of the main reasons why trailing return types are helpful is that the arguments to the function or function template you are writing are able to be refered to when forming the return type, however, when dealing with non-static member functions, it seems to me that you are not able to refer to "this" or non-static members. This greatly reduces the usefulness of trailing return types, as all of the reasons why you would want to refer to the parameters apply with the same rationale to why you would want to refer to members and "this". I've skimmed through the standard and see no explicit mention of or examples of using trailing return types in this manner. Perhaps someone here can help parse the standard-ese to clarify? I'd hope that you could refer to non-static members, but I see no evidence of that. One example of why this is frustrating in practice can be seen in the following hypothetical code for a Boost.Variant-style template with an "emplace" member-function that is intended to construct an object in-place similar to the emplace family of member functions of C++0x containers: http://codepaste.net/u5nfis Here, the trailing return type is used almost exclusively for extended SFINAE, though you often wish to refer to members in other cases as well where SFINAE isn't of any concern. The overall goal with the implementation of emplace being as such is to attempt to force substitution to fail if any of the following cases were true: if "Type" does not have a constructor taking the forwarded arguments if "Type" is not one of the types that is able to be stored in the template and possibly even something else I've missed (...which is a good thing...) Essentially we want substitution to fail if the instantiation of the body would fail, giving a very basic equivalent to low-level, syntax-only, automatic concept-checking. The benefit of this speaks for itself. Here, at least in my opinion, such code is very concise, very powerful, and surprisingly readable. Without such functionality of trailing return types we can only do marginally better than we've been doing for the past 10 years. So if someone could help me determine whether or not what I'm trying to do is standard I'd be grateful, and if such functionality is not standard, is it too late for it to be added? It seems to me that the benefits with respect to library development here are too great for a community like Boost to ignore, though I myself am not familiar enough with the standardization process to make an impact. Thanks. It appears this rant has overshadowed the original question, though please don't forget to respond. -- -Matt Calabrese

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Schedule on www.boost.org
by Rene Eng 14 Oct '10

14 Oct '10

Hi all Following the release schedule on www.boost.org, preparations for the release 1.45 are already underway. But I have not read anything here on the mailing list yet. Could somebody please either confirm the intention to keep those release dates, or otherwise adjust the dates in the release schedule? Thank you very much in advance René Eng -- “Dubito ergo cogito; cogito ergo sum. (I doubt, therefore I think; I think therefore I am)” René Descartes

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[geometry]
by Paul Blampspied 13 Oct '10

13 Oct '10

I have been looking at the advance version of [boost][geometry]. I think it is very useful and very well worked out. I have a question. Does [geometry] support the idea of a frame of reference ? I believe not, but it may be that I have missed some way of achieving this. By reference frame I mean that some points are not directly comparable if they are in different frames of reference. This is distinct from different coordinate systems (I think). For example we could have two geographic coordinate systems, one referring to lat./long. on earth and another to Mars. the points on these two reference frames should not be comparable and should give a compile error. Can this be done in [geometry] ? More interestingly we could use two distinct reference frames for convenience, even though there is a known relation between them. It would be nice if point conversions between the two frames could be carried out (possibly implicitly). For example, I would like to do something like this: ShiftAndRotateTransform<EgocentricFrame, WorldFrame> EgoFrame_WorldFrame_Transform(10, 20, 90); //Shift by [10,20] and rotate 90deg. WorldFrame Test() { WorldFrame p1 = EgoFrame(0,0); EgocentricFrame p2 = WorldFrame(p1); return p2; //IMPORTANT - p2 is implicitly transformed to WorldFrame when returned from Test function. } I have managed to implement a very simple scheme which allows this to compile and work successfully, but I am not completely satisfied with my homebrew scheme. In particular, I am forced to declare the WorldFrame and EgoFrame classes and provide all the constructors for them. It is necessary to explicitly provide constructors for all the reference frames which can be converted - implying that this is known at the time the class is written. It is more flexible to use overloaded functions, because these can be added as required e.g. //The second argument is the output point which is modified. ChangeReferenceFrame(WorldFrame &p1, EgocentricFrame &p2); ChangeReferenceFrame(EgocentricFrame &p1, WorldFrame &p2); ChangeReferenceFrame(EgocentricFrame &p1, SomeNewFrameType &p2); However the syntactic convenience and possibility of implicit conversion is lost. I wonder if some sleight of template magic could allow the extensibility of the second approach with the usability of the first. The starting point would be to allow a class representing the transform between the two frames of reference to be declared. This should attempt to define as much of the machinery as possible. It seems to me that these facilities have no impact on the existing design of [geometry], but concern an extension to allow reference frames to be defined and related.

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License question
by David Bellot 13 Oct '10

13 Oct '10

Hi guys, I'm working on a new library for some specific A.I and machine learning problems and I will release it as a Free Software of course. However, I wonder if you guys can enlighten me regarding license. This library will be template-based for some parts and compiled for other parts. I don't want to restrict users in what they're doing with the library, I mean they can use it for open-source or closed-source products. However, I want to decently protect my work and because it's template-based and can be used in commercial products, I don't want someone to do closed-source fork of it and all those kind of things... I selected to candidates: Boost and LGPL. So question: - do I have to use a Boost license or a LGPL license ? - and why not using GPL directly or is it too restrictive ? Thanks for your help, David (also boost::ublas maintainer when not doing statistics ;-) ) -- David Bellot, PhD david.bellot(a)gmail.com http://david.bellot.free.fr

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Re: [boost] [function] function wrapping with no exception safety guarantee
by Dave Abrahams 12 Oct '10

12 Oct '10

On Tuesday, October 12, 2010, Emil Dotchevski <emil(a)revergestudios.com> wrote: > On Tue, Oct 12, 2010 at 4:04 PM, Daniel Walker > <daniel.j.walker(a)gmail.com> wrote: >> Formally, boost::function invocation has strong exception safety if >> invoking the target function has strong exception safety. > > This makes no sense at all. Invoking boost::function always has strong > exception safety guarantee. In no way it can make the state of the > boost::function object inconsistent, because it does not modify its > state. Sounds like you're talking about the basic guarantee here. > _____________________________________________ -- Dave Abrahams BoostPro Computing http://www.boostpro.com

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Nightly tests failed with filesystem problem
by Belcourt, Kenneth 12 Oct '10

12 Oct '10

Hi, Tests failed last night for a problem with v3/src/operations.cpp. gcc.compile.c++ /scratch/boost/boost/bin.v2/libs/filesystem/build/ gcc-4.1.2/release/link-static/v3/src/operations.o "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall - DBOOST_ALL_NO_LIB=1 -DBOOST_SYSTEM_STATIC_LINK=1 -DNDEBUG -I"/scratch/ boost/ boost" -c -o "/scratch/boost/boost/bin.v2/libs/filesystem/build/ gcc-4.1.2/release/link-static/v3/src/operations.o" "/scratch/boost/ boost/libs/filesystem/v3/src/operations.cpp" /scratch/boost/boost/libs/filesystem/v3/src/operations.cpp: In function ‘boost::filesystem3::file_type<unnamed>::query_file_type(const boost::filesystem3::path&, boost::system::error_code*)’: /scratch/boost/boost/libs/filesystem/v3/src/operations.cpp:467: error: no matching function for call to ‘symlink_status(const boost::filesystem3::path&, boost::system::error_code*&)’ /scratch/boost/boost/boost/filesystem/v3/operations.hpp:209: note: candidates are: boost::filesystem3::file_status boost::filesystem3::symlink_status(const boost::filesystem3::path&) /scratch/boost/boost/boost/filesystem/v3/operations.hpp:211: note: boost::filesystem3::file_status boost::filesystem3::symlink_status(const boost::filesystem3::path&, boost::system::error_code&) Can someone please take a look? Thanks. -- Noel

1 0

[proto] Writing a transform to get at an inner constant of a transform result type
by Sebastian Redl 12 Oct '10

12 Oct '10

Hi, The subject is probably very confusing. I'm back to playing with a proto-based library for vector types. I have a basic underlying vector template, simd_impl: template <typename T> struct simd_impl { static const size_t size = VECTOR_BYTES / sizeof(T); // data }; And I have a grammar, Simd struct Simd : proto::or_< SimdLiteral, SimdUnary, SimdVectorBinary, SimdMixedBinary > {}; where SimdLiteral is an enumeration of proto::terminal<simd_impl<T>> where T are various underlying types, SimdUnary are unary operations, SimdVectorBinary are combinations of two vectors, and SimdMixedBinary are combinations of vectors with scalars. SimdVectorBinary is currently defined approximately like this: struct SimdVectorBinary : proto::or_< proto::when<proto::plus<Simd, Simd>, exec::simd_plus(Simd(_left), Simd(_right))>, // more operators here > {}; Now I want to validate, in the grammar, that you only add two vectors of the same arity together. That is, I'm fine with adding simd_impl<long> and simd_impl<int> together if they have the same size, because both have the same number of elements, but adding simd_impl<short> and simd_impl<int> together doesn't work, as one has twice the number of elements as the other. But I can't figure out how to write a grammar that validates this. I've started something like this: struct VSizeMatches : proto::if_<mpl::equal_to<Arity(proto::_left), Arity(proto::right)>()> {}; but I think that's wrong, and I can't figure out how to write Arity anyway. Basically, I have to find the simd_impl<T> type that the result of my Simd transform has and then access the size member. But I'm kinda afraid that this will get me into a world of trouble with prematurely instantiated templates. Any advice? Sebastian

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Re: [boost] [Review] Formal Review of Proposed Boost.RatioLibrary IS UNDERWAY
by Tan, Tom (Shanghai) 12 Oct '10

12 Oct '10

Hi, Here my review. ----- Original Message ----- From: "Anthony Williams" <anthony.ajw(a)gmail.com> Subject: [boost] Reminder: [Review] Formal Review of Proposed Boost.RatioLibrary IS UNDERWAY >> Here are some questions you might want to answer in your review: >> >> - What is your evaluation of the design? As others already mentioned, it follows the C++ Standards Committee's current Working Paper. That's good. >> - What is your evaluation of the implementation? - Code is clear and easy to read and understood. - BOOST_INTMAX_C is the only macro that's defined in ratio.hpp but not staring with BOOST_RATIO_. As the name suggests, it'll be better 1) if placed in boost/cstdint.hpp, or 2)be named as BOOST_RATIO_INTMAX_C indicating that it's used for boost.ratio only, I personally prefer option 1). - I would expect the comments are better cleaned up and the style unified. Right now, //, //-, //~, /**/ are all used, which seems confusing. I personally like the style adopted in boost.asio. >> - What is your evaluation of the documentation? - It's always a pleasure to read documents generated with BoostBook Documentation Format, - In the tutorial section, it'll be great if more examples are appended so that one example for each supported arithmetic and comparison operations, considering boost.ratio is a small one, doing so won't explode the tutorial section but gives a more complete picture of the lib. >> - What is your evaluation of the potential usefulness of the library? I can think of two scenarios: 1) It could quite useful in physical measurement of time, length, weight and the like where values of different units are being calculated. 2) It could be useful in expressing large rational number (Can anyone please let me know whether ratio is short for rational or a complete word itself? It seems either is OK, though I still wonder) >> - Did you try to use the library? With what compiler? Did you have any problems? Yes, indirectly through using boost.chrono, which is based on boost.ratio. VC10 on Windows 7, GCC4.4 w/ mingwin on widows 7. GCC4.4 on Ubuntu 10.4 No problem with the latest version from boost sandbox. >> - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? I did have some in-depth reading of previous versions of the code & documentation while I was started using boost.chrono, though not line by line. I also did a deep reading of C++ Standards Committee's current Working Paper (n2661in order to understand the why and how of ratio class then. While doing this review, I had a thorough reading of the code and documentation, which costs about half a day (including expressing my comments in English). >> - Are you knowledgeable about the problem domain? Intermediate. >> - Do you think the library should be accepted as a Boost library? Yes.

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construe_cast, call for interest and feedback
by Jeroen Habraken 11 Oct '10

11 Oct '10

Hi, I'm proud to say I've tagged a version 0.2 of construe_cast some minutes ago. For those unfamiliar with the library (it's the first time I'm posting this to the boost mailinglist), it's a library which builds upon boost.spirit to create a cast-like operator aiming to provide an alternative to lexical_cast providing greater speed and flexibility. The current code can be found at http://github.com/VeXocide/construe_cast and should be compatible with boost version 1.42.0 and up. What can it do, in short, boost::construe_cast<int>("23") and boost::construe_cast<std::string>(23); (and a lot of other types, basically the ones boost.spirit supports). Secondly, since this release, boost::construe_cast<std::string, tag::bin>(23) resulting in a std::string("10111") and visa versa. The user has the ability to add functionality here by implementing extra tags, by default tag::bin, tag::oct and tag::hex are implemented, with more to follow. What I'm hoping to add the coming weeks: - Documentation, I'm somewhat ashamed to say this hasn't been written yet, however, this will be tackled shortly. - Support for different encodings, it currently uses standard (ASCII) and standard_wide for wchar_t, with more to follow. - A nothow version, like lexical_cast it currently throws when it encounters a run-time, an interface returning false or a default value will be included (the exact interface hasn't been decided upon yet). Performance, now this is where it gets hard. I've done some basic benchmarking and it's somewhere between one and five times as fast as lexical_cast, depending on what you're casting. Good compilers (I've notices this with gcc 4.4 and up for example) are actually capable of optimizing boost::construe_cast<int>("23") to the integer 23 at compile-time which makes it tricky to benchmark. If anyone with more benchmarking experience is willing to look into this, please do. Again, thanks to everyone who helped me get this far, and Hartmut in particular. There seems to be little to add at the moment, I'm looking forward to your opinions and insights. Regards, Jeroen Habraken P.S. I've had a few responses about the name, construe is an english word (http://www.thefreedictionary.com/construe) and I'm using construe_cast as a working name. If people are ever going to consider this for inclusion with boost, changing the name will surely be the least of my worries.

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[units] missing merge of autoprefix to release
by Jürgen Hunold 11 Oct '10

11 Oct '10

Hi ! I was quite surprised that the "autoprefix" feature is not available in the current release branch. I found that the merge from the development branch to trunk was done in r62532. The issue is https://svn.boost.org/trac/boost/ticket/3660 Any chance this can be merged to release ? Yours, Jürgen -- * Dipl.-Math. Jürgen Hunold ! Ingenieurgesellschaft für * voice: ++49 511 262926 57 ! Verkehrs- und Eisenbahnwesen mbH * fax : ++49 511 262926 99 ! Lister Straße 15 * juergen.hunold(a)ivembh.de ! www.ivembh.de * * Geschäftsführer: ! Sitz des Unternehmens: Hannover * Prof. Dr.-Ing. Thomas Siefer ! Amtsgericht Hannover, HRB 56965 * PD Dr.-Ing. Alfons Radtke !

2 3

[Review] Formal Review of Proposed Boost.Ratio Library FINAL DAY
by Anthony Williams 11 Oct '10

11 Oct '10

Hi everyone, Today is the FINAL DAY for the review of Vicente Botet' Ratio library. If you haven't already posted a review, please do so today. What is it? ======== Portable implementation of the C++0x Standard Library's compile-time rational arithmetic working on C++03 and C++0x compilers. See the current C++0x working draft at http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2010/n3126.pdf Boost.Ratio provides: * A class template, ratio, for specifying compile time rational constants such as 1/3 of a nanosecond or the number of inches per meter. ratio represents a compile time ratio of compile time constants with support for compile time arithmetic with overflow and division by zero protection * It provides a textual representation of boost::ratio<N, D> in the form of a std::basic_string. Other types such as boost::duration can use these strings to aid in their I/O. This library is header-only and is designed to be generic and useful in a lot of areas of math and numerics C++ programming, in particular it is absolutely needed for the proposed Boost.Chrono and Boost.Stopwatches libraries which are currently in the review queue. Getting the library ============= The latest version of this library may be downloaded from vault: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=ratio.… SVN: http://svn.boost.org/svn/boost/sandbox/chrono (directories boost/ratio and libs/ratio) and the docs may be viewed here html: http://svn.boost.org/svn/boost/sandbox/chrono/libs/ratio/doc/html/index.html pdf: http://svn.boost.org/svn/boost/sandbox/chrono/libs/ratio/doc/ratio.pdf You can get all these information also (which should avoid some long links) from http://svn.boost.org/trac/boost/wiki/LibrariesUnderConstruction#Boost.Ratio It is worth noting that the tests included in the zip file are relatively sparse. Vicente has an extensive suite of tests licensed under the LLVM license. He has posted a message on the Boost Developers mailing list regarding the license requirements for tests (See http://thread.gmane.org/gmane.comp.lib.boost.devel/208978) and is awaiting the outcome of that discussion before making the tests available. Writing a review ================ If you feel this is an interesting library, then please submit your review to the developer list (preferably), or to the review manager. Here are some questions you might want to answer in your review: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick - reading? In-depth study? - Are you knowledgeable about the problem domain? And finally, every review should answer this question: - Do you think the library should be accepted as a Boost library? Be sure to say this explicitly so that your other comments don't obscure your overall opinion. Anthony Review Manager for the proposed Boost.Ratio library -- Author of C++ Concurrency in Action http://www.stdthread.co.uk/book/ just::thread C++0x thread library http://www.stdthread.co.uk Just Software Solutions Ltd http://www.justsoftwaresolutions.co.uk 15 Carrallack Mews, St Just, Cornwall, TR19 7UL, UK. Company No. 5478976

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Boost Evolution
by Robert Ramey 11 Oct '10

11 Oct '10

Boost is getting bigger and bigger. This is a good thing. The Boost header directory and boost namespace is also getting bigger and bigger. This is starting to become a problem. I would like to see: a) new libraries not add headers to boost directory or namespace. - with the possible exception - of "convenience headers" which include all the other headers for a library. Personally I don't like these, but since one doesn't have to use them its not a huge deal. b) authors of existing libraries which are implemented in boost directory/namespace would be encouraged to migrate them to a lower level. c) a couple of "catch all" namespaces/headers would be required such as "utility" for small libraries. I'm somewhat confused about "detail". If it's an implemenation detail of a particular library it should be in that library. If its a useful function which is shared by several libraries, it should be in something like: "unreviewed". And of course these should have thier test and documenations in the corresponding "lib" subdirectory. As boost get's bigger and bigger, it gets harder and harder to install just a part of it. But installing just a part of it is what users need to become confident about it. I realize that we've been circling around this topic for a while, I just want to keep it alive. Robert Ramey

9 16

[Review] Final Few Days for Formal Review of Proposed Boost.Ratio Library
by Anthony Williams 10 Oct '10

10 Oct '10

Hi everyone, If you have already posted a review, then thank you. For the rest of you: the review of Vicente Botet' Ratio library runs until October 11th, 2010 (this coming Monday), so please submit your reviews. What is it? ======== Portable implementation of the C++0x Standard Library's compile-time rational arithmetic working on C++03 and C++0x compilers. See the current C++0x working draft at http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2010/n3126.pdf Boost.Ratio provides: * A class template, ratio, for specifying compile time rational constants such as 1/3 of a nanosecond or the number of inches per meter. ratio represents a compile time ratio of compile time constants with support for compile time arithmetic with overflow and division by zero protection * It provides a textual representation of boost::ratio<N, D> in the form of a std::basic_string. Other types such as boost::duration can use these strings to aid in their I/O. This library is header-only and is designed to be generic and useful in a lot of areas of math and numerics C++ programming, in particular it is absolutely needed for the proposed Boost.Chrono and Boost.Stopwatches libraries which are currently in the review queue. Getting the library ============= The latest version of this library may be downloaded from vault: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=ratio.… SVN: http://svn.boost.org/svn/boost/sandbox/chrono (directories boost/ratio and libs/ratio) and the docs may be viewed here html: http://svn.boost.org/svn/boost/sandbox/chrono/libs/ratio/doc/html/index.html pdf: http://svn.boost.org/svn/boost/sandbox/chrono/libs/ratio/doc/ratio.pdf You can get all these information also (which should avoid some long links) from http://svn.boost.org/trac/boost/wiki/LibrariesUnderConstruction#Boost.Ratio It is worth noting that the tests included in the zip file are relatively sparse. Vicente has an extensive suite of tests licensed under the LLVM license. He has posted a message on the Boost Developers mailing list regarding the license requirements for tests (See http://thread.gmane.org/gmane.comp.lib.boost.devel/208978) and is awaiting the outcome of that discussion before making the tests available. Writing a review ================ If you feel this is an interesting library, then please submit your review to the developer list (preferably), or to the review manager. Here are some questions you might want to answer in your review: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick - reading? In-depth study? - Are you knowledgeable about the problem domain? And finally, every review should answer this question: - Do you think the library should be accepted as a Boost library? Be sure to say this explicitly so that your other comments don't obscure your overall opinion. Anthony Review Manager for the proposed Boost.Ratio library -- Author of C++ Concurrency in Action http://www.stdthread.co.uk/book/ just::thread C++0x thread library http://www.stdthread.co.uk Just Software Solutions Ltd http://www.justsoftwaresolutions.co.uk 15 Carrallack Mews, St Just, Cornwall, TR19 7UL, UK. Company No. 5478976

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Variadic Data Library in sandbox
by Edward Diener 09 Oct '10

09 Oct '10

I have put in the sandbox the Variadic Macro Data library, or VMD. This library supplies variadic macro functionality and integrates variadic macros with the Boost PP library without changing the latter in any way. The library in the sandbox is in the variadic_macro_data folder. The library is a header-only library of macros. There is documentation and tests and the appropriate jamfiles for both. To build the documentation you need doxygen but I have also provided documentation in an html subfolder. The main use of the library is to be able to pass variadic data to macros, and in particular to extract variadic data elements or convert variadic data to Boost PP data types for use by Boost PP. The library also enhances the Functionality of Boost PP tuple data. Installation is simply to take the boost and lib subfolders of the library and copy them to a Boost installation, preferable the trunk where support for variadic macros has been added in Boost config in the form of a BOOST_NO_VARIADIC_MACROS which is defined for compilers/versions which do NOT support variadic macros. To use the macros in the library, just "#include <boost/variadic_macro_data/VariadicMacroData.hpp>". Compilers which support variadic macros are gcc 3.0 and above and VC8 ( VS2005 ) and above among a few others. There is a discussion in the doc of why you might choose to use variadic macros rather than a Boost PP data type in a macro tailored for end-users. Comments, suggestions, and bug reports are welcome. Edward Diener

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[Locale] Stream manipulator bug
by Alexander Lamaison 09 Oct '10

09 Oct '10

The latest version of Boost.Locale is doing something wierd to stream manipulators. For example, the following code should print 63:2c:7f. If you uncomment the line that sets the global locale to use a boost::locale instance, it prints 990:440:127. It seems to be ignoring the std::hex manipulator and doing something strange with std::width. #include <iomanip> #include <iostream> #include <sstream> #include <string> #include <vector> #include <boost/locale.hpp> std::string hexify() { std::ostringstream hex_hash; hex_hash << std::hex << std::setfill('0'); unsigned int data[] = {99, 44, 127}; for(size_t i = 0; i < 3; ++i) { if (!hex_hash.str().empty()) hex_hash << ":"; hex_hash << std::setw(2) << data[i]; } return hex_hash.str(); } int main() { using boost::locale::generator; generator gen; //std::locale::global(gen("")); std::cout << hexify() << std::endl; } This is on Windows 7 with Boost.Locale compiled to only use the Win32 backend. Alex -- Easy SFTP for Windows Explorer (http://www.swish-sftp.org)

2 1

[Review] Boost.Ratio
by joel falcou 09 Oct '10

09 Oct '10

So here is my review of Boost.Ratio *- What is your evaluation of the design?* It's a strictly (or at least as struct as possible) implementation of the standard proposal. Code is clear and easily followed. *- What is your evaluation of the implementation?* It's very OK and straightforward. I'll reiterate the question about providing MPL or Fusion adaptors as an optional features (unless I missed them :x) *- What is your evaluation of the documentation?* Good *- What is your evaluation of the potential usefulness of the library?* Ratio fills a gap in the MPl-like data type and enables new interesting design to be done. *- Did you try to use the library? With what compiler? Did you have any problems? * I tried it using gcc 4.4 and 4.5 and icc 11. No problem so far. *- How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? * I quickly glanced over the code as I knew it from its inception and followed it so I only had to look some new stuff. I tried some non trivial task , including some attempt at MPL like CT linear system solver using rational. boost.ratio proved itself useful in this task. *- Are you knowledgeable about the problem domain? * Yes. *- Do you think the library should be accepted as a Boost library?* Yes

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[Boost][Proto] Fw:[Spirit-general] Patch for compiling Karma without RTTI
by Bryce Lelbach 08 Oct '10

08 Oct '10

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Forwarding from the spirit-general mailing list. Begin forwarded message: Date: Fri, 08 Oct 2010 12:01:55 +0800 From: Joel de Guzman <joel(a)boost-consulting.com> To: spirit-general(a)lists.sourceforge.net Subject: Re: [Spirit-general] Patch for compiling Karma without RTTI On 10/8/2010 10:34 AM, Bryce Lelbach wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Summary: > > 0x0.) There's a workaround header for compilers without > typeinfo/typeid in boost/detail/sp_typeinfo.hpp. It has a few macros > that uses real typeid/typeinfo if it exists, and the workaround if > not. The workaround was broken on GCC 4.5.1 and clang (rebuilt daily > from upstream trunk). I fixed the problem (static initialization > jazz). > > 0x1.) Spirit's hold_any uses typeinfo/typeid. I changed it to use > the aforementioned macros. > > 0x2.) Some debugging stuff in one proto file used RTTI. I changed > it to use the aforementioned macros. > > I haven't had a need for Qi/Lex yet. I'm currently putting the > finishing touches on the ariel driver. My intention is to use Qi for > my lightweight command line parsing needs, because it will be less > painful than spending half an hour browsing through LLVM doxygen to > figure out how their cl parser works. So, there might be another one > of these patches in the morning. > > Patch was generated via svn diff from the top of my local copy of the > Boost trunk (on Debian GNU/Linux). I suggest sending an email to the Boost mailing list non-spirit related patches (and accompanying explanations). We don't have control over those parts (e.g. proto and boost/detail/sp_typeinfo.hpp) Regards, - -- Joel de Guzman http://www.boostpro.com http://spirit.sf.net - ------------------------------------------------------------------------------ Beautiful is writing same markup. Internet Explorer 9 supports standards for HTML5, CSS3, SVG 1.1, ECMAScript5, and DOM L2 & L3. Spend less time writing and rewriting code and more time creating great experiences on the web. Be a part of the beta today. http://p.sf.net/sfu/beautyoftheweb _______________________________________________ Spirit-general mailing list Spirit-general(a)lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/spirit-general - -- Bryce Lelbach aka wash http://groups.google.com/group/ariel_devel -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEARECAAYFAkyumQMACgkQO/fqqIuE2t63WwCg2lT+hIeoy9xISTU73PwRE/FD G9sAoNQwHDIMMPYO1GbDiWYP0lco/crH =iU+P -----END PGP SIGNATURE-----

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Re: [boost] [Spirit-general] construe_cast, call for interest and feedback
by Jeroen Habraken 07 Oct '10

07 Oct '10

On 7 October 2010 22:43, Aaron Graham <aaron(a)aarongraham.com> wrote: > I'm excited about construe_cast. I always liked the flexibility of > lexical_cast, but tend not to use it as much as I could because of its > performance relative to other mechanisms. > Does gcc still convert "23" at compile time if you disable builtins? > (-fno-builtin) > #include <boost/construe_cast.hpp> int main(int, char**) { return boost::construe_cast<int>("23"); } compiled using gcc 4.5.1, g++-4.5 test.cpp -o test -O3 -I . -I ../library/boost-trunk/ -fno-builtin will generate the following code: Dump of assembler code for function main: 0x0000000100000e20 <main+0>: push %rbp 0x0000000100000e21 <main+1>: mov $0x17,%eax 0x0000000100000e26 <main+6>: mov %rsp,%rbp 0x0000000100000e29 <main+9>: leaveq 0x0000000100000e2a <main+10>: retq 0x0000000100000e2b <main+11>: nopl 0x0(%rax,%rax,1) thus as you can see, it's still able to perform the optimization. Jeroen

1 0

[Review] Formal Review of Proposed Boost.Ratio Library Starts TODAY
by Anthony Williams 07 Oct '10

07 Oct '10

Hi everyone, The review of Vicente Botet' Ratio library starts TODAY (October 2nd) and lasts until October 11th, 2010, unless an extension occurs. What is it? ======== Portable implementation of the C++0x Standard Library's compile-time rational arithmetic working on C++03 and C++0x compilers. See the current C++0x working draft at http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2010/n3126.pdf Boost.Ratio provides: * A class template, ratio, for specifying compile time rational constants such as 1/3 of a nanosecond or the number of inches per meter. ratio represents a compile time ratio of compile time constants with support for compile time arithmetic with overflow and division by zero protection * It provides a textual representation of boost::ratio<N, D> in the form of a std::basic_string. Other types such as boost::duration can use these strings to aid in their I/O. This library is header-only and is designed to be generic and useful in a lot of areas of math and numerics C++ programming, in particular it is absolutely needed for the proposed Boost.Chrono and Boost.Stopwatches libraries which are currently in the review queue. Getting the library ============= The latest version of this library may be downloaded from vault: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=ratio.… SVN: http://svn.boost.org/svn/boost/sandbox/chrono (directories boost/ratio and libs/ratio) and the docs may be viewed here html: http://svn.boost.org/svn/boost/sandbox/chrono/libs/ratio/doc/html/index.html pdf: http://svn.boost.org/svn/boost/sandbox/chrono/libs/ratio/doc/ratio.pdf You can get all these information also (which should avoid some long links) from http://svn.boost.org/trac/boost/wiki/LibrariesUnderConstruction#Boost.Ratio It is worth noting that the tests included in the zip file are relatively sparse. Vicente has an extensive suite of tests licensed under the LLVM license. He has posted a message on the Boost Developers mailing list regarding the license requirements for tests (See http://thread.gmane.org/gmane.comp.lib.boost.devel/208978) and is awaiting the outcome of that discussion before making the tests available. Writing a review ================ If you feel this is an interesting library, then please submit your review to the developer list (preferably), or to the review manager. Here are some questions you might want to answer in your review: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick - reading? In-depth study? - Are you knowledgeable about the problem domain? And finally, every review should answer this question: - Do you think the library should be accepted as a Boost library? Be sure to say this explicitly so that your other comments don't obscure your overall opinion. Anthony Review Manager for the proposed Boost.Ratio library -- Author of C++ Concurrency in Action http://www.stdthread.co.uk/book/ just::thread C++0x thread library http://www.stdthread.co.uk Just Software Solutions Ltd http://www.justsoftwaresolutions.co.uk 15 Carrallack Mews, St Just, Cornwall, TR19 7UL, UK. Company No. 5478976

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[Concept Check] ContiguousIterator
by joel falcou 07 Oct '10

07 Oct '10

Using BCC, s there any way to refine RandomAccessIterator so the cocnept captures the fact that the address of two consecutive value iterated over are contiguous in memory ? I can't get any proper expression to check for this in a proper way.

6 7

[xpressive] Support for multi-capture and balancing groups
by Erik Rydgren 07 Oct '10

07 Oct '10

Hi! My company have been using pcre for a long while but there has been gripes about it only returning the last matched value from a capture group. Because of this I have been searching for a C++ regex engine that can handle the same stuff as the .NET implementation can do, to no avail. During my searches I've stumbled on several forum threads where others have been searching for the same thing but it doesn't seem to exist a regular expression library in C/C++ that handles both named captures and multicapture. Found boost.xpressive and it had almost everything we need. It's open source, fast, got flexible api and named captures. But alas, just as all other C and C++ based implementations I have found, it lacked multiple captures. So, I added it. On top of that I added support for balancing groups (http://blog.stevenlevithan.com/archives/balancing-groups) But the syntax for the pop capture and capture conditional is slightly different then the .NET version to better fit xpressive. Syntax for pop capture: dynamic: (?P<-name>stuff) static: (name -= stuff) Syntax for capture conditional: dynamic: (?P(name)stuff) static: (name &= stuff) There is no support for the (?<name-othername>stuff) construct. All captures made by a group is stored in sub_match::captures which is a vector of sub_match_capture objects. A sub_match_capture behaves like a stripped down sub_match. It can be put in an ostream and has a length and helper function for returning a string. The changes are in the vault and can be found here: http://tinyurl.com/3aak7mp It can be unpacked against trunk from 2010-10-02 or the 1.44.0 release. I've run the dynamic regression tests without errors and I have added some tests for the new functionality. The code it only tested on Visual Studio 2010 since I don't have access to any other compiler. Please give feedback on my changes since I would love to see them in an official release. Thanks in advance. Regards, Erik

3 6

[fusion] for_each
by Christophe Henry 06 Oct '10

06 Oct '10

Hi, I have 2 fusion containers: a small vector (my_vec) and a bigger set (my_set). I want to overwrite the elements of the set with elements from the vector whenever they have the same type. Sounds simple: struct update { update(my_set_type& to_overwrite_):to_overwrite(to_overwrite_){} template<typename T> void operator()(T& elt) /*const?*/ { boost::fusion::at_key<T>(to_overwrite)=elt; } my_set_type& to_overwrite; }; boost::fusion::for_each(my_vec,update(my_set)); Except that this won't compile because the operator() is required to be const, which is sad, because it was very simple. This leaves me with the unattractive option of inverting the set and the vector inside update. Now, I iterate on the set's elements and overwrite them when found in the vector. This is unattractive because 1) the code gets really ugly 2) it could be slower (the set is bigger) and 3) it has a much bigger compile-time cost (I resorted to an enable_if of fusion::result_of::find and I make it short, it is actually much worse). I thought of using transform, but this will be slower as I will need to transform every element of the set, even for a vector of size 1. Am I missing something? If not, would it be possible to remove this constraint? Thanks, Christophe

4 6

[Range] Composite Range
by Robert Jones 06 Oct '10

06 Oct '10

Is there any facility supported in Boost to provide a 'composite' range? I.e., a range that might be a vector, followed by a bit of list, followed by a pair of iterators? I guess the iterator classification of such a range would be the lowest common denominator of the classifications of all the component iterators, and I don't even want to think about how sort() would work, but it might be quite handy. - Rob.

3 4

[Review] Formal Review: Boost.Ratio
by Anthony Williams 06 Oct '10

06 Oct '10

Hi everyone, The review of Vicente Botet' Ratio library starts October 2nd and lasts until October 11th, 2010, unless an extension occurs. What is it? ======== Portable implementation of the C++0x Standard Library's compile-time rational arithmetic working on C++03 and C++0x compilers. See the current C++0x working draft at http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2010/n3126.pdf Boost.Ratio provides: * A class template, ratio, for specifying compile time rational constants such as 1/3 of a nanosecond or the number of inches per meter. ratio represents a compile time ratio of compile time constants with support for compile time arithmetic with overflow and division by zero protection * It provides a textual representation of boost::ratio<N, D> in the form of a std::basic_string. Other types such as boost::duration can use these strings to aid in their I/O. This library is header-only and is designed to be generic and useful in a lot of areas of math and numerics C++ programming, in particular it is absolutely needed for the proposed Boost.Chrono and Boost.Stopwatches libraries which are currently in the review queue. Getting the library ============= The latest version of this library may be downloaded from vault: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=ratio.… SVN: http://svn.boost.org/svn/boost/sandbox/chrono (directories boost/ratio and libs/ratio) and the docs may be viewed here html: http://svn.boost.org/svn/boost/sandbox/chrono/libs/ratio/doc/html/index.html pdf: http://svn.boost.org/svn/boost/sandbox/chrono/libs/ratio/doc/ratio.pdf You can get all these information also (which should avoid some long links) from http://svn.boost.org/trac/boost/wiki/LibrariesUnderConstruction#Boost.Ratio It is worth noting that the tests included in the zip file are relatively sparse. Vicente has an extensive suite of tests licensed under the LLVM license. He has posted a message on the Boost Developers mailing list regarding the license requirements for tests (See http://thread.gmane.org/gmane.comp.lib.boost.devel/208978) and is awaiting the outcome of that discussion before making the tests available. Writing a review ================ If you feel this is an interesting library, then please submit your review to the developer list (preferably), or to the review manager. Here are some questions you might want to answer in your review: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick - reading? In-depth study? - Are you knowledgeable about the problem domain? And finally, every review should answer this question: - Do you think the library should be accepted as a Boost library? Be sure to say this explicitly so that your other comments don't obscure your overall opinion. Anthony Review Manager for the proposed Boost.Ratio library -- Author of C++ Concurrency in Action http://www.stdthread.co.uk/book/ just::thread C++0x thread library http://www.stdthread.co.uk Just Software Solutions Ltd http://www.justsoftwaresolutions.co.uk 15 Carrallack Mews, St Just, Cornwall, TR19 7UL, UK. Company No. 5478976

5 6

[fusion] for_each
by Christophe Henry 06 Oct '10

06 Oct '10

I think it's at least partly my mistake. It took me some time to manage a limited example not compiling: #include <boost/fusion/container/set.hpp> #include <boost/fusion/container/vector.hpp> #include <boost/fusion/include/at_key.hpp> #include <boost/fusion/include/for_each.hpp> #include <boost/fusion/include/as_vector.hpp> struct A { int adata; }; struct B { int bdata; }; struct C { int cdata; }; typedef boost::fusion::set<A, B, C> my_set_type; typedef boost::fusion::vector<A, B> my_vector_type; struct update { update(my_set_type& to_overwrite_):to_overwrite(to_overwrite_){} template<typename T> void operator()(T& elt) const { boost::fusion::at_key<T>(to_overwrite)=elt; } my_set_type& to_overwrite; }; int main() { my_set_type my_set; my_vector_type my_vec; boost::fusion::for_each(boost::fusion::as_vector(my_vec),update(my_set)); } Now it will compile if you replace boost::fusion::as_vector(my_vec) by my_vec or T& by T const&. Ok so it seems my problem description is wrong and I needed to know that as_vector returns a const vector, right? Thanks, Christophe

1 0

Differences between Boost.Thread and std?
by David Abrahams 05 Oct '10

05 Oct '10

Hi All, Is there a document somewhere describing the differences between Boost.Thread and what's being proposed for C++0x? Thanks, -- Dave Abrahams BoostPro Computing http://www.boostpro.com

3 2

Re: [boost] [fusion] for_each
by Christophe Henry 05 Oct '10

05 Oct '10

>> I have 2 fusion containers: a small vector (my_vec) and a bigger set >> (my_set). I want to overwrite the elements of the set with elements >> from the vector whenever they have the same type. Sounds simple: >> >> struct update >> { >> update(my_set_type& to_overwrite_):to_overwrite(to_overwrite_){} >> template<typename T> >> void operator()(T& elt) /*const?*/ >> { >> boost::fusion::at_key<T>(to_overwrite)=elt; >> } >> my_set_type& to_overwrite; >> }; >> >> boost::fusion::for_each(my_vec,update(my_set)); >> >> Except that this won't compile because the operator() is required to >> be const, which is sad, because it was very simple. > > And it won't compile *with* the const? I don't think the const'ness of > the member function affects the const'ness of the referent of to_overwrite. No, it won't compile ;-)

2 1

[serialization] assert missing
by Andrew Sutton 05 Oct '10

05 Oct '10

The header 'boost/serialization/item_version_type.hpp' seems to be missing an include on boost/assert.hpp (or cassert) that was causing some compilation failures in the graph_parallel tests (under GCC-4.4.3 on GNU/Linux x86_64). The test case brings this in by including serialization/list.hpp. My first thought was to simply stick an appropriate #include in the item_version_type. Would there be any problems committing this change? Andrew

1 0

[Review] Formal Review of Proposed Boost.Ratio Library Starts TODAY
by nimaca2001＠libero.it 05 Oct '10

05 Oct '10

> > - What is your evaluation of the design? > - What is your evaluation of the implementation? Take this as the review from an average C++ user that uses uses simple boost stuff like shared_ptr or bind but is scared of things like MPL or Spirit. > - What is your evaluation of the documentation? Well written, I would have omitted some appendixes (F and G). > > - Did you try to use the library? With what compiler? Did you have any problems? Tried the provided samples and some self written one on MSVC 9 without problems despite the fact I was using an old version of boost (1.41) as base. > > - How much effort did you put into your evaluation? A glance? A quick > - reading? In-depth study? About one hour to read the docs and compile a few tests > > And finally, every review should answer this question: > > - Do you think the library should be accepted as a Boost library? Yes

2 1

[fusion] [intro] ADAPT_STRUCT extensions
by Stefan Strasser 04 Oct '10

04 Oct '10

Hi, in the discussion about the library I called "Intro" at the time it has been suggested to use BOOST_FUSION_ADAPT_STRUCT of Boost.Fusion for data member access. based on that I'd like to propose two extensions to ADAPT_STRUCT, which I think are useful beyond my use case: 1) ADAPT_STRUCT can adapt public data members only. with the modifications I uploaded here: http://svn.boost.org/svn/boost/sandbox/intro/boost/fusion/adapted/struct/ all data members can be adapted. for example: class A{ private: friend class fusion::access; int a; }; BOOST_FUSION_ADAPT_STRUCT(A,(int,a) ) 2) adaption of a class including its base class members. for example: struct A{ int a; }; struct B{ int b; }; struct C : A,B{ int c; } BOOST_FUSION_ADAPT_STRUCT(A,(int,a) ) BOOST_FUSION_ADAPT_STRUCT(B,(int,b) ) BOOST_FUSION_ADAPT_DERIVED( C, (A)(B), (int,c) ) an instance of C is now a fusion sequence of size 3. http://svn.boost.org/svn/boost/sandbox/intro/boost/fusion/adapted/struct/ad… private inheritance is supported as above, virtual inheritance is not. I'm not sure if virtual inheritance can be supported.

8 30

Boost.SQL?
by Roland Bock 04 Oct '10

04 Oct '10

Hi, currently I am working on a set of header files which are supposed to make the life of C++ developers easier when in comes to interacting with databases (based on SQL). Goals are: * Stay close to SQL syntax * Do as much type checking as possible * prevent oversights and typical security holes, e.g. by forgetting to escape strings The basic idea is, that given a table definition, it should be possible to * offer a lot of checks at compile time for building a query * make it hard to misinterpret the results Until now, I have been concentrating on table definitions and select statements. Here's a very simplistic example, assuming a table definition "my_table" and a database connection "db": // ------------------------------------------------------------------------- using boost; typedef my_table<> t; typedef sql::select_record<t> record; std::string name("Peter"); ... std::vector<record> records = db.select<record>( sql::where(t::id() > 1000 && t::first_name() == name), sql::order_by(t::priority()(sql::desc)), sql::limit(17)); // the values can be accessed by their name // and are of the correct type, e.g. records.front().first_name_; // is a string records.front().middle_name_; // optional<string> because the table definition says that it can be NULL // In case of a select from more than one table, the values can also be accessed like this records.front().my_table_.first_name; // ------------------------------------------------------------------------- I wonder if there would be interest for such a library in boost.

17 44

[config] additions for gcc 4.0.1 and IBM V11.1.0.0duetoMSM compile errors
by Christophe Henry 04 Oct '10

04 Oct '10

John Maddock wrote: > The updated test is passing as well, looks like this may be a case of adding > a BOOST_WORKAROUND for Apple's GCC and see if it fixes things. I added some #if for Apple's gcc and the IBM compiler. A look at the regression tests (http://www.boost.org/development/tests/trunk/developer/msm.html) shows: - all problems with Apple's gcc 4.0.1 are gone (waow cool! Better than expected) - IBM's compiler manages a few test cases more (for others, it just crashes or gives a run-time error status 139 which does not bring me much further) This is in my eyes a proof that for these compilers, BOOST_NO_NESTED_FRIENDSHIP and BOOST_NO_MEMBER_TEMPLATE_FRIENDS should be defined. If these features only work sometimes, then they should not be seen as supported. We now have 2 possibilities: - we change boost.config to reflect this situation and I update my code accordingly - we don't and I have to keep my #if. Solution 2 is not great for me because I'm duplicating boost.config and it litters my code with stuff less clear than BOOST_NO_NESTED_FRIENDSHIP and BOOST_NO_MEMBER_TEMPLATE_FRIENDS. In any case, it'd be good if we could decide on it this week on it so that this makes it to the 1.45. Thanks, Christophe

1 0

[btree] build advice needed
by Phil Endecott 04 Oct '10

04 Oct '10

Dear Beman & others, At the risk of appearing ignorant and being told the RTM, can someone please help me to build btree? I am attempting to do this on a smallish ARM Linux box where building the whole of Boost is impractical (but which should otherwise be very similar to an x86 Linux system). So far: # apt-get install g++ (etc) # apt-get install boost-build # apt-get install bjam # apt-get install git $ git clone git://github.com/Beman/Boost-Btree btree $ cd btree/libs/btree/build $ bjam error: Could not find parent for project at '.' error: Did not find Jamfile or project-root.jam in any parent directory. As it says, there is no project-root.jam or Jamfile in any parent; this makes me think that perhaps it is expecting this to be part of a larger Boost tree. Or, maybe I just don't know the right incantations. What's the easiest way to go about this? If I do need to get other Boost source code, if there some git magic that will do it for me? Thanks, Phil.

3 3

[thread] Memory leak in Boost.Thread?
by Denis Arnaud 03 Oct '10

03 Oct '10

Hello, a Fedora user has reported a potential memory leak in Boost.Thread (see https://bugzilla.redhat.com/show_bug.cgi?id=627875 for details), detected with Valgrind in (at least) versions 1.41.0 and 1.44.0. Following is a code snippet allowing to reproduce the issue: ==================================== #include <boost/thread.hpp> void someWork() { double a; for(int i= 0;i< 1000;i++) { a+=log((double)i); } } int main() { for(int i = 0; i< 10; ++i) { boost::thread_group pool; for(int j = 0; j< 100; ++j) { pool.create_thread(someWork); } pool.join_all(); } } ==================================== Then, following is Valgrind's report: ==================================== ==6442== Memcheck, a memory error detector ==6442== Copyright (C) 2002-2009, and GNU GPL'd, by Julian Seward et al. ==6442== Using Valgrind-3.5.0 and LibVEX; rerun with -h for copyright info ==6442== Command: ./boost_leak ==6442== ==6442== ==6442== HEAP SUMMARY: ==6442== in use at exit: 8 bytes in 1 blocks ==6442== total heap usage: 5,967 allocs, 5,966 frees, 701,720 bytes allocated ==6442== ==6442== 8 bytes in 1 blocks are still reachable in loss record 1 of 1 ==6442== at 0x4C2615D: malloc (vg_replace_malloc.c:195) ==6442== by 0x4E3F989: boost::detail::get_once_per_thread_epoch() (in /usr/lib64/libboost_thread-mt.so.1.44.0) ==6442== by 0x4E39923: ??? (in /usr/lib64/libboost_thread-mt.so.1.44.0) ==6442== by 0x4E39BC8: boost::detail::get_current_thread_data() (in /usr/lib64/libboost_thread-mt.so.1.44.0) ==6442== by 0x4E3A528: boost::this_thread::interruption_enabled() (in /usr/lib64/libboost_thread-mt.so.1.44.0) ==6442== by 0x4E3A548: boost::this_thread::disable_interruption::disable_interruption() (in /usr/lib64/libboost_thread-mt.so.1.44.0) ==6442== by 0x404DC4: boost::shared_mutex::lock() (in /tmp/boost_leak) ==6442== by 0x40588D: boost::lock_guard<boost::shared_mutex>::lock_guard(boost::shared_mutex&) (in /tmp/boost_leak) ==6442== by 0x405DB5: boost::thread* boost::thread_group::create_thread<void (*)()>(void (*)()) (in /tmp/boost_leak) ==6442== by 0x403B91: main (in /tmp/boost_leak) ==6442== ==6442== LEAK SUMMARY: ==6442== definitely lost: 0 bytes in 0 blocks ==6442== indirectly lost: 0 bytes in 0 blocks ==6442== possibly lost: 0 bytes in 0 blocks ==6442== still reachable: 8 bytes in 1 blocks ==6442== suppressed: 0 bytes in 0 blocks ==6442== ==6442== For counts of detected and suppressed errors, rerun with: -v ==6442== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 6 from 6) ==================================== Is that really a memory leak? Kind Regards Denis

3 5

[filesystem] Issue with replace_extension
by cheesy4poofs 02 Oct '10

02 Oct '10

I've recently switched all our code to filesystem v3 and added BOOST_FILESYSTEM_NO_DEPRECATE on our builds for good measure. One of the changes I had to fix was our use of change_extension(), which was modified to use the replace_extension() method. However, some of our code started failing and I tracked it down to this example: boost::filesystem::path p("C:\\database\\test\\filename"); p.replace_extension(".db"); std::cout << p.string() << std::endl; // OUTPUT - C:\database\test\filename.db p = "C:\\database.1\\test\\filename"; p.replace_extension(".db"); // bug? std::cout << p.string() << std::endl; // OUTPUT - C:\database.db As you can see, in the second example, it truncates the path and assumes the directory name "database.1" has the extension that needs replacing. change_extension() did not behave this way. Is this the expected behavior? Thanks, Scott

2 1

[ratio] Mini-review of the proposed ratio library
by Beman Dawes 02 Oct '10

02 Oct '10

> The review of Vicente Botet' Ratio library starts October 2nd and lasts > until October 11th, 2010, unless an extension occurs. > > What is it? > ======== > Portable implementation of the C++0x Standard Library's compile-time > rational arithmetic working on C++03 and C++0x compilers. See the > current C++0x working draft at > http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2010/n3126.pdf > - What is your evaluation of the design? The question is essentially moot since Vicente followed the C++0x standard library design. The real question is "Does Boost need a library that every standard library vendor will be supplying anyhow?" For me, the answer is, yes, at least provisionally. The provisional part is because the library I'd really like to see in Boost in chrono. But we can't have <boost/chrono.hpp> without <boost/ratio.hpp>, so I'm in favor of ratio. The reason I'd like a Boost version is that I don't want to have to wait years and years to be able to use <boost/chrono.hpp> and <boost/ratio.hpp> in Boost libraries. I want to be able to use them with the compilers and standard libraries people are using today, not years from now. > - What is your evaluation of the implementation? I am familiar with the original source code, and worked on boostifying it. Vicente has done a lot of work to make the code more robust in the Boost environment. > - What is your evaluation of the documentation? I skimmed through it, and checked the header against the C++ standard. My impression is favorable. > - What is your evaluation of the potential usefulness of the library? Chrono needs it:-) > - Did you try to use the library? With what compiler? Did you have any problems? No. > - How much effort did you put into your evaluation? A glance? A quick > - reading? In-depth study? A quick skim through the docs. > - Are you knowledgeable about the problem domain? Some knowledge, but far from an expert. > And finally, every review should answer this question: > > - Do you think the library should be accepted as a Boost library? Yes. I'm hoping others will post more in depth reviews. My review is really just a mini-review, but maybe will help to keep the ball rolling. --Beman

3 4

Boost ABI compatibility analysis at linuxtesting.org
by Mateusz Loskot 02 Oct '10

02 Oct '10

Hi, I've searched the list archives and I don't find any posts referring to this interesting resource. The http://linuxtesting.org hosts reports of ABI analysi performed by ABI compatibility checker [1] tool against number of open source libraries [2]. Boost included [3]. [1] http://ispras.linux-foundation.org/index.php/ABI_compliance_checker [2] http://linuxtesting.org/upstream-tracker/index.html [3] http://linuxtesting.org/upstream-tracker/versions/boost.html Best regards, -- Mateusz Loskot, http://mateusz.loskot.net Charter Member of OSGeo, http://osgeo.org Member of ACCU, http://accu.org

2 2

[boost::bind] How does it works for overloaded member functions in this example?
by Chaos A.D. 02 Oct '10

02 Oct '10

Hi there! Recently I was extremely surprised by the fact that boost::bind can handle the case of binding overloaded member functions! Here is the simplified testcase, which works fine in gcc 4.4.3. #include <boost/bind.hpp> struct Test { static void Func(int) {}; static void Func(int, const char*) {}; }; int main(int argc, char **argv) { boost::bind(&Test::Func, 5)(); boost::bind(&Test::Func, 5, "WORKS!")(); return 0; } In full testcase i tried to reproduce simplified boost::bind logic, and ensured, that my simplified version is still incorrect: #include <boost/bind.hpp> template <class A1> class Args1 { template <class Fn> void call(Fn fn) { fn(a1); } A1 a1; }; template <class A1, class A2> class Args2 { template <class Fn> void call(Fn fn) { fn(a1, a2); } A1 a1; A2 a2; }; template <class Fn, class Args> struct bind_t { bind_t( Fn fn, Args const& args ) : fn_(fn), args_(args) {} void operator()() { args_.call(fn_); } private : Fn fn_; Args args_; }; template <class Fn, class A1> bind_t< Fn, Args1<A1> > bind(Fn fn, A1 a1) { typedef Args1<A1> args; return bind_t<Fn, args>(args(a1)); } template <class Fn, class A1, class A2> bind_t< Fn, Args2<A1, A2> > bind(Fn fn, A1 a1, A2 a2) { typedef Args2<A1, A2> args; return bind_t<Fn, args>(args(a1, a2)); } struct Test { static void Func(int) {}; static void Func(int, const char*) {}; }; int main(int argc, char **argv) { boost::bind(&Test::Func, 5)(); boost::bind(&Test::Func, 5, "WORKS!")(); bind(&Test::Func, 5)(); bind(&Test::Func, 5, "NOT WORKS!")(); return 0; }

4 3

[btree] Large file support
by Beman Dawes 01 Oct '10

01 Oct '10

The btree library uses low level I/O. On POSIX-like systems that means read/write/lseek. lseek() won't support large files on systems where long is 32 bits. POSIX-like operating systems get around this problem by supply functions with names like llseek or lseek64 that traffic in long long instead of long. So there is a line of code: new_offset = ::lseek(handle(), offset, whence); // offset is a variable of type int64_t That needs to change to something like: #if defined(SOMEOS) new_offset = ::|lseek(handle(), offset, whence); #elif defined(ANOTHEROS) new_offset = ::whatever(handle(), offset, whence); #else new_offset = ::lseek(handle(), offset, whence); #endif Up at the front of the source file there may also have to be special headers included or symbols defined, depending on the operating system. I'd appreciate some help from folks familiar with particular non-Windows operating systems. What is the preferred name for the 64-bit seek function and what is the preferred #if defined(symbol)? Do special headers have to be included or special symbols defined? Thanks, --Beman

4 3

[1.43.0] [variant] Compilation errors when swapping variant type objects
by Adam Badura 01 Oct '10

01 Oct '10

We are using Boost 1.43.0 (we tried to move to 1.44.0 but there were some problems which I reported some time ago) in Visual Studio 2010. And there are some compilation problems when variant type objects are swapped. This does not affect all variant types but I didn't figured out what are the exact conditions (however I guess it is likely something with namespaces and templates). Following code demonstrates the issue: ---------------------------------------- #include <cstdlib> #include <list> #include <boost/variant.hpp> int main() { typedef boost::variant< std::list< int >::iterator > variant_type; variant_type v; variant_type().swap( v ); return EXIT_SUCCESS; } ---------------------------------------- compilation fails with following message: ---------------------------------------- 1>d:\libraries\boost_1_43_0\boost\variant\detail\move.hpp(155): error C2668: 'boost::detail::variant::detail::move_swap::swap' : ambiguous call to overloaded function 1> d:\libraries\boost_1_43_0\boost\variant\detail\move.hpp(141): could be 'void boost::detail::variant::detail::move_swap::swap<T>(T &,T &)' 1> with 1> [ 1> T=T0 1> ] 1> c:\program files\microsoft visual studio 10.0\vc\include\utility(100): or 'void std::swap<T>(_Ty &,_Ty &)' [found using argument-dependent lookup] 1> with 1> [ 1> T=T0, 1> _Ty=T0 1> ] 1> while trying to match the argument list '(T0, T0)' 1> d:\libraries\boost_1_43_0\boost\variant\variant.hpp(698) : see reference to function template instantiation 'void boost::detail::variant::move_swap<T>(T &,T &)' being compiled 1> with 1> [ 1> T=T0 1> ] 1> d:\libraries\boost_1_43_0\boost\variant\variant.hpp(825) : see reference to function template instantiation 'void boost::detail::variant::swap_with<Variant>::operator ()<T>(T &) const' being compiled 1> with 1> [ 1> Variant=boost::variant<std::_List_iterator<std::_List_val<int,std::allocator<int>>>>, 1> T=T0 1> ] 1> d:\libraries\boost_1_43_0\boost\variant\detail\visitation_impl.hpp(141) : see reference to function template instantiation 'void boost::detail::variant::invoke_visitor<Visitor>::internal_visit<T>(T &,int)' being compiled 1> with 1> [ 1> Visitor=boost::detail::variant::swap_with<boost::variant<std::_List_iterator<std::_List_val<int,std::allocator<int>>>>>, 1> T=T0 1> ] 1> d:\libraries\boost_1_43_0\boost\variant\detail\visitation_impl.hpp(169) : see reference to function template instantiation 'void boost::detail::variant::visitation_impl_invoke_impl<Visitor,VoidPtrCV,T>(int,Visitor &,VoidPtrCV,T *,boost::mpl::false_)' being compiled 1> with 1> [ 1> Visitor=boost::detail::variant::invoke_visitor<boost::detail::variant::swap_with<boost::variant<std::_List_iterator<std::_List_val<int,std::allocator<int>>>>>>, 1> VoidPtrCV=void *, 1> T=T0 1> ] 1> d:\libraries\boost_1_43_0\boost\variant\detail\visitation_impl.hpp(252) : see reference to function template instantiation 'void boost::detail::variant::visitation_impl_invoke<Visitor,VoidPtrCV,T0,NoBackupFlag>(int,Visitor &,VoidPtrCV,T *,NoBackupFlag,int)' being compiled 1> with 1> [ 1> Visitor=boost::detail::variant::invoke_visitor<boost::detail::variant::swap_with<boost::variant<std::_List_iterator<std::_List_val<int,std::allocator<int>>>>>>, 1> VoidPtrCV=void *, 1> NoBackupFlag=boost::variant<std::_List_iterator<std::_List_val<int,std::allocator<int>>>>::has_fallback_type_, 1> T=T0 1> ] 1> d:\libraries\boost_1_43_0\boost\variant\variant.hpp(1769) : see reference to function template instantiation 'void boost::detail::variant::visitation_impl<first_which,first_step,Visitor,VoidPtrCV,boost::variant<T0_>::has_fallback_type_>(const int,const int,Visitor &,VoidPtrCV,boost::mpl::false_,NoBackupFlag,Which *,step0 *)' being compiled 1> with 1> [ 1> Visitor=boost::detail::variant::invoke_visitor<boost::detail::variant::swap_with<boost::variant<std::_List_iterator<std::_List_val<int,std::allocator<int>>>>>>, 1> VoidPtrCV=void *, 1> T0_=std::_List_iterator<std::_List_val<int,std::allocator<int>>>, 1> NoBackupFlag=boost::variant<std::_List_iterator<std::_List_val<int,std::allocator<int>>>>::has_fallback_type_, 1> Which=first_which, 1> step0=first_step 1> ] 1> d:\libraries\boost_1_43_0\boost\variant\variant.hpp(1780) : see reference to function template instantiation 'void boost::variant<T0_>::internal_apply_visitor_impl<Visitor,void*>(int,int,Visitor &,VoidPtrCV)' being compiled 1> with 1> [ 1> T0_=std::_List_iterator<std::_List_val<int,std::allocator<int>>>, 1> Visitor=boost::detail::variant::invoke_visitor<boost::detail::variant::swap_with<boost::variant<std::_List_iterator<std::_List_val<int,std::allocator<int>>>>>>, 1> VoidPtrCV=void * 1> ] 1> d:\libraries\boost_1_43_0\boost\variant\variant.hpp(1803) : see reference to function template instantiation 'void boost::variant<T0_>::internal_apply_visitor<boost::detail::variant::invoke_visitor<Visitor>>(boost::detail::variant::invoke_visitor<Visitor> &)' being compiled 1> with 1> [ 1> T0_=std::_List_iterator<std::_List_val<int,std::allocator<int>>>, 1> Visitor=boost::detail::variant::swap_with<boost::variant<std::_List_iterator<std::_List_val<int,std::allocator<int>>>>> 1> ] 1> d:\libraries\boost_1_43_0\boost\variant\variant.hpp(1637) : see reference to function template instantiation 'void boost::variant<T0_>::apply_visitor<boost::detail::variant::swap_with<Variant>>(Visitor &)' being compiled 1> with 1> [ 1> T0_=std::_List_iterator<std::_List_val<int,std::allocator<int>>>, 1> Variant=boost::variant<std::_List_iterator<std::_List_val<int,std::allocator<int>>>>, 1> Visitor=boost::detail::variant::swap_with<boost::variant<std::_List_iterator<std::_List_val<int,std::allocator<int>>>>> 1> ] 1> d:\libraries\boost_1_43_0\boost\variant\variant.hpp(1631) : while compiling class template member function 'void boost::variant<T0_>::swap(boost::variant<T0_> &)' 1> with 1> [ 1> T0_=std::_List_iterator<std::_List_val<int,std::allocator<int>>> 1> ] 1> d:\test\simple\simple.cpp(10) : see reference to class template instantiation 'boost::variant<T0_>' being compiled 1> with 1> [ 1> T0_=std::_List_iterator<std::_List_val<int,std::allocator<int>>> 1> ] ---------------------------------------- Adam Badura

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