- Boost - lists.boost.org

boost serialization and alignment
by meir shoham 04 Feb '09

04 Feb '09

Hi, When I'm setting struct member alignment as 1 BYTE in visual studio 2005 project environment (C++), I receive alignment error coming from boost serialization library (STATIC_ASSERT) at compilation time. This problem does not happen when I wrap the structures containing the boost serialization template methods using #pragma pack(push,1) and #pragms pack(pop). I'm using boost only to serialize/deserialize strctures and classes to/from XML. Is there a problem for boost serialization library to handle alignment other then the default one? Thanks, Meir

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Re: [boost] Coverity Static Code Analysis
by Michael Fawcett 03 Feb '09

03 Feb '09

On Tue, Feb 3, 2009 at 3:10 PM, Marshall Clow <marshall(a)idio.com> wrote: > > fixed, but I think that someone with a bit of legal training needs to look > at the license that Coverity wants people to agree to before using the scan > results. [ It looks pretty harmless to me, but IANAL ] > > <http://scan.coverity.com/policy.html#license> I agree. Doesn't Boost have access to just that sort of support? --Michael Fawcett

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Interest in a library for building simulations of dynamical systems?
by Jay Graham 03 Feb '09

03 Feb '09

Is there interest in a library for building simulations of dynamical systems represented by time-based differential equations? The proposed library would implement ideas found in the C++ Model Developer (CMD) library developed by Ray Sells, but in a more generic way. For example, the proposed library would support the use of user defined data types when defining states and their derivatives. Other CMD features to be included in the proposed library are: 1. The ability to mix both continuous and discrete events. 2. Support for a simulation structure that makes it easy to go from a mathematical description of a system to code. 3. Support for time-varying system topologies (e.g., multi-stage missiles). 4. User extendable set of numerical integration algorithms. For more information on CMD see: http://www.dtic.mil/srch/doc?collection=t2&id=ADA433836 and http://rocket.itsc.uah.edu/u/education/files/R/IPT_Producer/AIAA/Sells/Sell… Code snippet: // Define states and their derivatives struct x_pos : state< double, // state type double // derivative type > {}; struct y_pos : state< double, double > {}; // Define a simulation object struct Ball: obj< rk4, // fourth-order Runge-Kutta numerical integration algorithm mpl::vector< x_pos, y_pos > // State vector > { Ball(double x, double y, double vx, double vy) { // Initial state s_<x_pos>().value = x; s_<y_pos>().value = y; this->vx = vx; this->vy = vy; // Integrators add_integrator<x_pos>(this->vx); add_integrator<y_pos>(this->vy); } template< typename S, typename C > inline void update(S &sim, C &clock) { // Update the derivatives vx = 0.8*vx; vy = 0.8*vy; // Use a discrete event to stop the simulation // after 10 seconds if (clock.event(10.0)) { sim.halt(); } } template< typename C > void report(C &clock) { // Report current state at 1 second intervals if (clock.sample(1.0)) { std::cout << "Ball" << clock.t << " " << s_<x_pos>().value << " " << s_<y_pos>().value << "\n"; } } double vx; double vy; }; // Define the integration time-step struct dts { typedef double time_type; static time_type value() { return 0.01; } }; // Define a simulation stage struct stage_1 : stage< dts, mpl::vector<Ball> > {}; main() { // Create a simulation object Ball ball(0.0, 0.0, 10.0, 5.0); // Create the simulation execution object sim< mpl::vector< stage_1 > > sim(); // Initialize the simulation stage sim.stage_<stage_1>().obj_<Ball>() = &ball; // Run the simulation run(sim); }

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[parallel_sort] Proposal
by Edouard A. 03 Feb '09

03 Feb '09

Howdy, I just finished the first working version of parallel_sort. It seems there is a lot of interest for this function in the C++ community, and in the boost community specifically, which is the motivation for this post. ;) My implementation is somewhat very different in nature from the one present in Intel's TBB. It's designed to take advantages of a multi-core user machine, it's not designed to run on a grid for massive sorting operation. It only uses the STL and the boost library. It doesn't have any fancy prerequisites, except having several cores to unleash its power! Current benchmarks on my Q6600 vs2008-64-bit default allocator: 2 threads : 160 % faster 4 threads : 260 % faster Keep in mind the Q6600 is not a real equivalent to a quad-cpu machine and that the default memory allocator is not multithreading friendly. It can be heavily customized. I already offer the possibility to choose between quick sorting and merge sorting, and for quick sorting I offer two pivot algorithms : fast or secure. Then you can of course specify a predicate and a fallback sorting algorithm for when you run out of threads. If you don't care to customize, no problem! Just write: parallel_sort<2>(v.begin(), v.end()); // sort with 2 threads There is still some work to be done, especially in the documentation area. Nevertheless, I think it's time to open up the code and start getting feedback. J As an added bonus I also offer to add my implementation of the smoothsort algorithm (with some hints from Steven). This algorithm is faster on sorted input but slower on random input. Cheers -- EA

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SCons script for building Boost
by Sergey Popov 03 Feb '09

03 Feb '09

I've searched the ML archive and found out that scons wasn't considered for adoption because nobody offered to reimplement boost build instructions in terms of SCons. I'd like to work on this. Is there a chance I'll be given commit access so I could make a boost-SCons branch? ;) I've attached my early WIP build script to this posting.

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Re: [boost] Review process question
by Christophe Henry 03 Feb '09

03 Feb '09

"John Maddock" schrieb im Newsbeitrag news:<343DA106BE604F22B7EF1BFF0A8515B8@acerlaptop>... > >> It is enough to specify which revision that is to be reviewed. > > > > Is it possible to change it after the submission request? It would allow > > me > > to make some bugfixes (if necessary) while being in the queue. > > I think bugfixes at that stage are fine: as long as there is a stable > version available somewhere, and as long as all the reviewers are refering > to the same version during the review - in other words try and keep things > stable during the review itself. > > HTH, John. > > _______________________________________________ > Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost > I think I got it now. Thanks! Christophe

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[typeof] BOOST_AUTO and move semantic emulation
by vicente.botet 03 Feb '09

03 Feb '09

Hi, given T&& f(); which is the type of v in auto v = f(); Is there any plan to adapt Boost.Typeof with move semantics, so the following works? BOOST_TYPEOF_REGISTER_TEMPLATE(boost::detail::thread_move_t, 1) BOOST_TYPEOF_REGISTER(T) boost::detail::thread_move_t<T> f(); BOOST_AUTO(v, f()); Thanks, Vicente

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[1.38][flyweight] permission to merge to release
by JOAQUIN M. LOPEZ MUÑOZ 02 Feb '09

02 Feb '09

Hi, I've just commited the following trivial fix to the trunk: https://svn.boost.org/trac/boost/changeset/50974 which only adds a missing std:: to a call to strcpy. The fix hasn't still cycled trough the trunk regression testers, but I've tested it locally with MSVC++ 8.0 and GCC 3.4.4 and everything's fine. Can I merge to release now? Do I wait for a trunk test cycle? No permission at all? Thank you, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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[LibrariesUnderConstruction] Thanks!
by Christophe Henry 02 Feb '09

02 Feb '09

Hi, I realized this morning that I didn't add Msm to the LibrariesUnderConstruction Wiki page. And what do I see? Already done! And with description and link to the Vault! I have no idea who did it, but I want to thank him! And offer him a bottle of Bordeaux wine (if I manage to pass it through the customs ;-) ) at the next occasion (Aspen?). Thanks a lot, Christophe

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[accumulators] why not operator+=?
by Neal Becker 02 Feb '09

02 Feb '09

A nit perhaps, but why not overload += to process samples?

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