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Interprocess: rbtree_best_fit ABI change from 1.53 to 1.55 ?
by Arunski, Kevin 22 Jan '14

22 Jan '14

Hello, I have been using a boost::interprocess::map stored in a managed mapped file segment, using the rb_best_fit allocation algorithm. I have observed that starting in boost 1.55, I cannot interoperate with instances of this allocator that were created by programs compiled by boost 1.53. It appears that the size of a boost::intrusive multiset object has changed, and this changes the representation of the rb_best_fit algorithm within the shared memory region. The toolchain is unchanged between the two programs, in both cases it is Visual Studio 2012 on x64, linked against the release runtime library. The only change is that one was compiled using boost 1.53, while the other was compiled with boost 1.55. Is this the expected behavior? Is there a way to utilize boost interprocess in this way with reasonable certainty that the shared memory representation of it will not change between boost releases?

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vector clock
by Kenneth Adam Miller 22 Jan '14

22 Jan '14

Does boost have either a vector clock or lamport clock of any kind?

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boost multiprecision & STL map - resubmit
by tridiak＠ihug.co.nz 21 Jan '14

21 Jan '14

Ok. Better framed question. The following is compiled on XCode 5.0.1. Clang : Apple LLVM version 5.0 (clang-500.2.79) (based on LLVM 3.3svn) Target: x86_64-apple-darwin12.5.0 Thread model: posix Boost v 1.55.0. Build 2.0-m12. Not sure how to fix it. map complains about constructor ambiguity and I am not sure how to fix it. I am a casual hobbyist programmer and not a C++ expert. Looking at boost headers confuses me. Any help would be appreciated. //--------------------------------------------------------------------- Header File #ifndef boostTest_test_h #define boostTest_test_h #include #include #include using namespace boost::multiprecision; typedef std::map TestMap; #endif //------------------------------------------------------------------------- C++ file #include #include "test.h" int main(int argc, const char * argv[]) { static TestMap tm; std::string s="hello"; int128_t n=128; tm[n]=s;

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odeint - solving an ODE with time-dependent parameter numerically
by Arijit Hazra 21 Jan '14

21 Jan '14

Hello All, I am trying to solve an ode with time-dependent parameters by using boost. I have just started using boost and I think boost library's odeint library is the best option for my problem. Would anyone please explain me how I can solve a Initial Value Problem --a system of ODE --with a time-dependent parameter. e.g. dy1/dt = a1(t) * y2 -b1(t)* y3 -c1(t) y1; dy2/dt = a2(t) * y1 -b2(t)* y1 -c2(t) y3; dy3/dt = a3(t) * y2 -b3(t)* y3 -c3(t) y1; y(0)=c; My idea so far after going through the manuals and help files. is that for fixed time-step if I form a vector of a,b,c and assume a,b,c to be constant over that time-period I can solve using boost library. But this is mathematically less accurate and computationally expensive as far my understanding .For solving an ODE numerically *y*˙(*t*)=*f*(*y*(*t*), *t*) generally the problem is all about function evaluation for explicit methods and Jacobian evaluation for Implicit methods at specific points in *t* and *y*. e.g a step of explicit Euler is *yn*+1=*yn*+(*tn*+1−*tn*)⋅*f*(*yn*,*tn*). For time-dependent parameter, treating it as part of *f*, the function evaluation (respectively, for implicit methods, also treat it as part of the Jacobian evaluation) is the standard procedure. A similar strategy applies to more complicated methods for solving ODEs (multistage methods such as Runge-Kutta, implicit methods for stiff systems, etc.). This strategy is different and mathematically more accurate than assuming parameters are constant over a time step like a multistage method. Would anyone please help me to solve this problem using boost? Thank you in advance. With Best Regards, Arijit Hazra

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Sort boost composite container
by Uthpal Urubail 21 Jan '14

21 Jan '14

I am having below composite container. I am looking to sort the container by member<CA,std::string,&CA::card> at the end. Can some one help me to achieve this? typedef multi_index_container< CA, indexed_by< ordered_unique< composite_key< CA, member<CA,std::string,&CA::name>, member<CA,std::string,&CA::displayName>, member<CA,std::string,&CA::card> > > > > duplicateBook; Regards, UJ

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[BGL] A* implementation
by Knut Krause 21 Jan '14

21 Jan '14

Hi, I'm still considering to use the BGL for my large scale path finding problem. Sadly I don't fully understand the implementation of A* used in boost. Does it use optimizations like bidirectional A* and so on or can I activate those somehow? I think otherwise I'd have to implement my own version of A*. Regards Knut

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Help regarding how to start
by Mihir Thakkar 21 Jan '14

21 Jan '14

I was having a look at the To-Do list & Challenges of BGL. I found few of them already implemented. I would like to contribute, I would appreciate if someone can help from where to find the things which are not yet implemented, (like if boost has an updated To-Do list) I am interested in GUI, mathematics and general algorithms. Thanks!

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Cross compiling boost Windows -> Arm
by Marius Adrian DOBRESCU 21 Jan '14

21 Jan '14

Hello. I have a problem compiling boost with arm-none-linux-gnueabi-g++ on Windows. Shared library dependencies paths seems to be hard-coded with Windows paths: Example: build\bin.v2\libs\filesystem\build\gcc-arm\release\target-os-linux\threading-multi\... I tried to build with --prefix. Not working. Hardcode-dll-paths not working too. Tried to specify an explicit -rpath. The so shared libraries are compiled with hard-coded paths inside, with backslash \\\ and I cannot use them on linux-arm. On stage directory they are hard-coded too. Any idea how can I disable this behavior and what options should I pass to boost and where? I want simple libraries without full rpaths and the build must be done on Windows with gcc-gnueabi. Thanks. Adrian

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[Serialization] 1.49 to 1.55 problems
by John M. Dlugosz 21 Jan '14

21 Jan '14

I did search for "serialization incompatible version" on Google and found issues regarding certain older versions. I checked the release notes as far back as were on the web site, and didn't see anything. I tried building a program with Boost 1.55, and found it would not interoperate with existing programs that were built with Boost 1.49. Taking the error at face value, I need to configure the code to write the old version. How would I do that? —John

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Using BGL for huge grid graphs
by Knut Krause 21 Jan '14

21 Jan '14

Hi, I'm planning on using the BGL on huge graphs the represent a grid where each vertex is a cell connected to it's 8 neighbours. I think something around 2,500,000,000 vertices would be a good number to approach but it would be great if it could handle (a lot) more later. If I got this graph I have to find the shortest path between two vertices. Does anyone here have experiences with graphs that large? Is this even worth a try on "normal" hardware? The edge weights would be stored in the vertices. So if you want to go from (a) to (b) you'd have to pay the cost stored in (b). The graph is not directed either. I read about BGLs CSR graph http://www.boost.org/doc/libs/1_55_0/libs/graph/doc/compressed_sparse_row.h… but since I honestly have no clue how to use BGL yet I thought I'd first hear your opinons. Regards Knut

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