December 2009 - Boost-users - lists.preview.boost.org

[BoostCon 2010] Final Call for Participation
by Hartmut Kaiser 24 Jan '10

24 Jan '10

Please distribute! -------------------------------- 4th Annual Boost Conference 2010 -------------------------------- Aspen CO, USA, May 10-14, 2010, www.boostcon.com Final Call for Participation -------------------------------- Important dates: Proposal submissions Extended to January 3, 2010 Proposals decisions sent January 25, 2010 (tentative program available) Fully scheduled program available February 10, 2010 Session materials due April 15, 2010 -------------------------------- We invite you to submit session proposals to the 4th Annual Boost Conference: BoostCon 2010 (Aspen CO, USA, May 10-14, 2010). Traditionally the main face-to-face event for all things Boost (www.boost.org), BoostCon 2010 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 two constituencies: Boost end-users and hard-core Boost library and tool developers. The program fosters interaction and engagement within and across those two 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 will change 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 * 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=boostcon10. 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 2010 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 boostcon10(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. 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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[iterators][range][rangeex] range concatenation
by Dmitry Vinogradov 12 Jan '10

12 Jan '10

Is it possible with Boost (or RangeEx) to concatenate ranges? Sample usage: template <class Range> void process_range(Range const &); std::vector<foo> v = ...; std::list<foo> l = ...; process_range(concat(v, l));

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Defining Statements with Proto
by David A. Greene 08 Jan '10

08 Jan '10

A few years ago, I asked how to define a grammar with Proto to match something like this: if_(expr) [ stmt, stmt, ... ].else [ stmt, stmt, ... ]; The answer was to do this: struct Grammar; struct ExpressionGrammar; struct StatementGrammar; struct Domain; template<typename Expr> struct Expression : proto::extends<Expr, Expression<Expr>, Domain> { typedef proto::extends<Expr, Expression<Expr>, Domain> base_type; Expression(Expr const & expr = Expr()) : base_type( expr ) {} }; struct Domain : proto::domain< proto::generator< Expression >, Grammar> {}; struct If {}; BOOST_PROTO_DEFINE_FUNCTION_TEMPLATE( 1 , if_ , Domain , (If) , BOOST_PP_SEQ_NIL ); // Here is the grammar for if_ statements // matches if_(e1)[e2] struct IfGrammar : boost::proto::subscript< boost::proto::arg< boost::proto::unary_expr< If, ExpressionGrammar >, >, StatementGrammar > {}; // An else_ "operator" template<typename Expr> struct Expression< Expr , typename enable_if<proto::matches<Expr, IfGrammar> >::type > : proto::extends<Expr, Expression<Expr>, Domain> { Expression() : else_(proto::make_expr<Else>(*this)) {}; proto::result_of::make_expr< Else, // else is now an "operator" Expression<Expr> const >::type const else_; }; // matches if_(e1)[e2].else_[e3] struct IfElseGrammar : boost:proto::subscript< boost::proto::arg< boost::proto::unary_expr< Else, IfGrammar >, >, StatementGrammar > {}; I didn't understand it then and I don't now. :) However, it seems to be obsolete since BOOST_PROTO_DEFINE_FUNCTION_TEMPLATE doesn't seem to exist anymore (it's not documented, anyway). So how would this be formulated in modern Boost.Proto? I'm guessing I will need an expression template wrapper (called Expression<> above) that uses some combination of BOOST_PROTO_BASIC_EXTENDS, BOOST_PROTO_EXTENDS_SUBSCRIPT and BOOST_PROTO_EXTENDS_FUNCTION. But of course not all statements have a valid operator() overload and no expressions do. I guess the grammar will take care of that, yes? I'm really puzzled about how to do the ".else_" part. I was hoping I could look to Phoenix to get a clue but it doesn't seem to use Proto. Any help? Thanks! -Dave

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[Math/Statistical Distributions+Random] Random number generation
by Marco Guazzone 07 Jan '10

07 Jan '10

Hi all! I'm a "boost newbie" so sorry for too trivial questions. Just trying to use boost for some statistical experiments, involving statistical distribution fitting, quantile generation (for goodness-of-fit tests), random variate generation, and so on. . The "Math/Statistical Distribution" library is great and almost complete. But I'm just curious why the random number generation (provided by the "Random" lib) and this library have not been integrated. For instance, the boost::random::exponential_distribution and the boost::math::exponential_distribution are two different worlds. I think a function like this below would be very helpful: --- [snip] --- template <typename Generator, typename RealType, typename Policy> inline RealType rand(Generator& rng, const exponential_distribution<RealType, Policy>& dist) { return -1.0 / dist.lambda() * std::log(1.0-rng()); } --- [snip] --- or something similar (e.g., rand implemented as a class method) In this case only two objects are needed: * boost::random::mersenne_twister * boost::math::exponential_distribution Instead, actually I have to keep different objects. For instance, for the exponential distribution: * boost::random::exponential_distribution * boost::random::mersenne_twister * boost::random::variate_generator * boost::math::exponential_distribution Unluckely I can't use boost::math::exponential_distribution in place of boost::random::exponential_distribution since boost::random::variate_generator expects a specific interface for the distribution. Well, what is the rationale behind the choice of this separation? Do you think would be useful to provide this kind of integration? Thank you very much in advance!! Cheers -- Marco

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[thread] Getting this warning message with optimization turn on
by Shiou Ming Lee 07 Jan '10

07 Jan '10

Hi, I'm building my program that depends on Boost.thread, but getting following warning message, only when compiler's optimization been turn on. C:/boost_1_41_0/boost/thread/win32/thread_heap_alloc.hpp: In member function `bool gUtil::GLog::LogWriterManager::startAsyncLogging(unsigned int)': C:/boost_1_41_0/boost/thread/win32/thread_heap_alloc.hpp:156: warning: 'heap_memory' might be used uninitialized in this function In the mentioned function, startAsyncLogging(unsigned int), there's only one line of code that involves Boost.thread: // loggingThread is class LogWriterManager's member, of boost::thread type. loggingThread = boost::thread(boost::bind(&LogWriterManager::loggingThreadFunc, this)); This happens for MinGW 3.4 on Windows Vista SP1 32-bits, but not for GCC 4.4 on Fedora 11 x86. The Boost release is of version 1.41.0. Any idea what should I do for this warning message? Or should I just leave optimization on and ignore this message? Thanks & Regards Shiou Ming

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[GIL] Packing to 6 bytes
by Eloi Du Bois 06 Jan '10

06 Jan '10

Hi, I have a question: I need to create a view that hold 12 bit channel data packed as follow: 0000R0000G0000B0000;0000R0000G0000B0000;0000R0000G0000B0000;.... Meaning that each channel is shifted by 4 bits. The pixel is holden on 48 bits = 6 bytes. I have created my view like as follow: /// My 12 bits special rgb packed to 6 bytes typedef const packed_channel_reference<uint64_t, 04, 12, true> rgb12_packed_channel0_t; typedef const packed_channel_reference<uint64_t, 20, 12, true> rgb12_packed_channel1_t; typedef const packed_channel_reference<uint64_t, 36, 12, true> rgb12_packed_channel2_t; typedef mpl::vector3<rgb12_packed_channel0_t, rgb12_packed_channel1_t, rgb12_packed_channel2_t> rgb12_packed_channels_t; typedef packed_pixel<packed_channel_value<48>, rgb12_packed_channels_t, rgb_layout_t> rgb12_packed_pixel_t; typedef view_type_from_pixel<rgb12_packed_pixel_t>::type rgb12_packed_view_t; The thing is that I would now like to copy data to another rgb16_view_t... But this is not working because, in my opinion, 48 bits is between 32 and 64. I have been thinking of the solution that Christian gave me and that consist on doing something like this: T p( pData, 0 ); for( typename DST_V::y_coord_t y = 0; y < height; ++y ) { typename DST_V::x_iterator it = dst.row_begin( y ); for( typename DST_V::x_coord_t x = 0; x < width; ++x ) { color_convert( *p, *it ); ++p; ++it; } } where T is a bit_aligned_pixel_iterator and DST_V=rgb16_view_t but this can't be working on my case because channels are shifted by 4 bits ! If you could help me, I would really appreciate. I think all those cases are a good robustness test for gil. Regards, Eloi.

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Re: [Boost-users] [unit_test_framework] checkpoints for BOOST_CHECK*?
by rozelak＠volny.cz 04 Jan '10

04 Jan '10

> > rozelak(a)volny.cz wrote: > >> rozelak(a)volny.cz wrote: > >> > >>> Is there a way how to achieve what I am looking > >>> for? > >>> >>> > >> Use BOOST_TEST_MESSAGE and set log level to message > >> >> > > > > Yes, I have read about this option and it works - > > thank you. I consider > > > it as not perfect, but working solution. > > > > However, I want to ask, if the idea of checkpoints > > could be generalised > > > and used during check failure printing as well (as > > has been suggested > > > in the example in my first post). > > I don't know boost source in depth, but it seems > > that BOOST_TEST_CHECKPOINT > > > just calls boost::unit_test::unit_test_log.set_checkpoint(...), > > > > > > > > which > > > stores the checkpoint info in unit_test_log (which > > is supposed to be > > > singleton). > > Would, therefore, be possible to print the checkpoint > > stored also when > > > test failure is printed? May I be helpfull somehow > > to do this? > > > > > Or is it against the idea of the checkpoints? > > > > I think the issue is that BOOST_CHECK and friends set > a checkpoint. > I see, you are right. It is set by BOOST_TEST_PASSPOINT() macro. Well, do you think, that it would be beneficial to define new macro, e.g. BOOST_TEST_FAILRECORD (please suggest a better name, if you have one)? The macro would be implemented in the way very similar to BOOST_TEST_CHECKPOINT, but the data "recorded" by the macro would be printed only when a testcase fails or an unexpected exception occurs. It also has the advantage, that when not used, it does not affect the current behaviour of boost. Is there a change to accept it in the boost test framework, if I try to implement it? Thank you for suggestions/comments, Dan

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[Wave] Modifying the way function-like macros are interpreted
by fractured＠modularsystems.sl 04 Jan '10

04 Jan '10

I am trying to use boost::wave as a preprocessor for LSL, a language used in the virtual world Second Life. There is a data type there for collections of data, but it can only be accessed through functions such as llList2String(list,iterator); I wanted to define macros that would allow me to do something like #define x[y] llList2String(x,y), however, wave as it stands does not seem to have any immediately obvious way to do this.

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[test] Unexpected Exceptions
by Florian Winter 04 Jan '10

04 Jan '10

Hi, What is the intended behavior of Boost.Test if an unexpected exception is thrown? Example: void do_not_throw() throw() { throw "unexpected"; } Some of my applications using Boost.Test seem exit with an error code of 0 (successful) if an unexpected exception is thrown. Is this the intended behavior? Best regards, fw

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alignment question
by Slawomir Lisznianski 03 Jan '10

03 Jan '10

I'm having trouble implementing properly aligned storage. The following example shows conceptually what I'm trying to do, but it's NOT a correct way of doing it. template <typename T> struct envelope { size_t len = sizeof(T); // <--- compiler may pad here, hence this doesn't work... T body; }; So, given an arbitrary type T, we want to create an envelope that will have the size of T immediately before it, with no padding between len and body. The user would then be able to: envelope<MyStruct> env; env.body.x = ... send(env); I'm curious if anyone has run into something similar and have a clean solution. Our code currently has to defer to temporary buffers and memcpy'ing data back to it. Thanks, Slaw

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