- Boost-users - lists.boost.org

installed version / build option
by Kraus Philipp 20 Aug '12

20 Aug '12

Hello, can I read the build / version of the installed Boost from a file? I would like to grep the version and multithread / singlethread install option from the Boost include directory. Thanks Phil

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Thread overhead
by Alireza Haghdoost 20 Aug '12

20 Aug '12

Hi Is there anyway to reduce overhead of threadFoo() call in this simple program ? class baseClass { public: void foo(){ boost::posix_time::milliseconds delay(143); boost::this_thread::sleep(delay); } void threadFoo(){ threadObjOne = boost::thread(&baseClass::foo, this); threadObjTwo = boost::thread(&baseClass::foo, this); threadObjOne.join(); threadObjTwo.join(); } private: boost::thread threadObjOne; boost::thread threadObjTwo; }; int main(){ std::cout<< "main startup"<<std::endl; baseClass baseObj; tick_t startTime,endTime; rdtscll(startTime); baseObj.foo(); rdtscll(endTime); std::cout<<"native foo() call takes "<< endTime-startTime <<" clock cycles"<<std::endl; rdtscll(startTime); baseObj.threadFoo(); rdtscll(endTime); std::cout<<"Thread foo() call takes "<< endTime-startTime <<" clock cycles"<<std::endl; } The output is : main startup native foo() call takes 368222398 clock cycles Thread foo() call takes 372600905 clock cycles

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Re: [Boost-users] boost::math::standard_deviation how to use ?
by Edouard Tallent 19 Aug '12

19 Aug '12

My 2-cent One can easily compute the standard deviation of data contained in a std::vector as shown here: http://stackoverflow.com/questions/7616511/calculate-mean-and-standard-devi… Another option is resorting on boost, and any boost container as here: http://www.boost.org/doc/libs/1_41_0/libs/math/doc/sf_and_dist/html/math_to… I mean I am not sure ** in this case *** trying to mix standard vector and boost is the best solution. Best Edouard https://quantcorner.wordpress.com/ ========= Message: 4 Date: Fri, 17 Aug 2012 13:15:50 -0700 (PDT) From: leeto <denisigoshev(a)gmail.com> To: boost-users(a)lists.boost.org Subject: [Boost-users] boost::math::standard_deviation how to use ? Message-ID: <1345234550791-4634435.post(a)n4.nabble.com> Content-Type: text/plain; charset=us-ascii How to compute standard_deviation using boost I want that interface will be like in excel i mean you mark some data and that all ) How do the same in c++ boost using data from a standard container like vector for example... Many thanks in advance #include <boost/math/distributions.hpp> // For non-member functions of distributions #include <vector> #include <numeric> using namespace std; int main () { std::vector<double> v; for (unsigned int i = 0; i < 7; i++) { v.push_back(std::rand()%7); } std::vector<double>::iterator i = v.begin(); for (i ; i != v.end(); ++i) { std::cout << (*i) << ", "; } cout << std::accumulate(v.begin(), v.end(),0) << endl; //boost::math::normal_distribution cout << "\n\n\n" ; return 0;

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Boost Style Guide ?
by Cowing-Zitron, Christopher 18 Aug '12

18 Aug '12

Hello, I am a relative newbie to C++, in that I have been using it for about a year, and am comfortable with using it, capable of reading complex code, able to create my own libraries, and familiar with (I think) all of the fundamental constructs. But what I have not yet cultivated is my own style, in terms of formatting, structure of packages (i.e. separation of declaration and definition, inclusion hierarchies), idioms, naming conventions, etc. Given that Boost is so well written, so highly respected and relied upon, and second only to the actual standard in terms of authority, I thought I might try emulating Boost style in my coding. To that end, is there an (un)official Boost Style Guide? Or can you recommend another library/set-of-libraries worth trying to emulate that does provide a style guide? Given that the software I write is all scientific/numerical libraries for machine learning and bioinformatics, should I even be looking to a utility/metaprogramming library like Boost for style inspiration? If not, can anyone recommend some C++ numerical libraries which display especially solid coding style and structure, even if they are not necessarily the optimal libraries in terms of their numerical properties? Thanks everybody, -- Chris

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undefined reference to boost::filesystem
by Thibaut Lepage 18 Aug '12

18 Aug '12

Hello, I can't link against the filesystem library. When I try to compile a program using boost::filesystem (like the simple one attached to this email), I get "undefined reference" errors from the linker: dourak@Vvardenfell:~$ g++ -o dummy dummy.cpp -lboost_filesystem -lboost_system /tmp/ccMpl6cj.o: In function `boost::filesystem::exists(boost::filesystem::path const&)': dummy.cpp:(.text._ZN5boost10filesystem6existsERKNS0_4pathE[boost::filesystem::exists(boost::filesystem::path const&)]+0x19): undefined reference to `boost::filesystem::detail::status(boost::filesystem::path const&, boost::system::error_code*)' /tmp/ccMpl6cj.o: In function `boost::filesystem::path::path<char*>(char* const&, boost::enable_if<boost::filesystem::path_traits::is_pathable<boost::decay<char*>::type>, void>::type*)': dummy.cpp:(.text._ZN5boost10filesystem4pathC2IPcEERKT_PNS_9enable_ifINS0_11path_traits11is_pathableINS_5decayIS4_E4typeEEEvE4typeE[_ZN5boost10filesystem4pathC5IPcEERKT_PNS_9enable_ifINS0_11path_traits11is_pathableINS_5decayIS4_E4typeEEEvE4typeE]+0x22): undefined reference to `boost::filesystem::path::codecvt()' collect2: ld a retourné 1 code d'état d'exécution I carefully sorted the libraries in the command line, since gcc has trouble with library dependencies, sometimes, but it still doesn't work. I use gcc 4.6.3 on Ubuntu 12.04 64bits. The problem occurs either with boost 1.46.1 (taken from the repositories) or with 1.50.0 (installed with bjam). Any hint ? Thibaut Lepage

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Setup Boost::Signals2 with Remote Objects?
by Clark Cianfarini 18 Aug '12

18 Aug '12

Hello, I am trying to develop a server/client set of applications in C++ that has the ability to be setup either all on one computer, or distributed across multiple machines (generally over an intranet). The goal is to have a possibility of N clients all connected to a single server. The server collects data from our various sensors, bundles it into a single object, and ideally triggers a Boost::Signal2, passing the object, to send the data to all subscribed clients. The resulting processing methods of each client would be the subscribed slots and thus the processing would automatically be triggered. The current software is designed this way through the use of .NET remoting, but we are trying to move away from being tied down to the Windows realm. I cannot seem to find documentation as to how to set up remote objects in such a way to connect the signals and slots across processes/computers. Do I have to do this through the use of Boost::MPI in some manner? Or do I need to change my thought process and use just Boost::MPI with object serialization to just pass the data? Or is there some third option I should be looking at instead? Thank you, Clark <mailto:ccianfarini@Lumetrics.com> ccianfarini(a)Lumetrics.com

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boost optional assignment
by tolik levchik 17 Aug '12

17 Aug '12

The following code gives me compilation error. With const reference it's ok. Is it right behaviour? #include <boost/optional.hpp> #include <boost/shared_ptr.hpp> struct foo{ // foo(int const& of) good foo(int& of) // error {} }; int main(){ boost::shared_ptr<int> ptr; boost::optional<foo> opt; opt = *ptr; }

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boost::math::standard_deviation how to use ?
by leeto 17 Aug '12

17 Aug '12

How to compute standard_deviation using boost I want that interface will be like in excel i mean you mark some data and that all ) How do the same in c++ boost using data from a standard container like vector for example... Many thanks in advance #include <boost/math/distributions.hpp> // For non-member functions of distributions #include <vector> #include <numeric> using namespace std; int main () { std::vector<double> v; for (unsigned int i = 0; i < 7; i++) { v.push_back(std::rand()%7); } std::vector<double>::iterator i = v.begin(); for (i ; i != v.end(); ++i) { std::cout << (*i) << ", "; } cout << std::accumulate(v.begin(), v.end(),0) << endl; //boost::math::normal_distribution cout << "\n\n\n" ; return 0; -- View this message in context: http://boost.2283326.n4.nabble.com/boost-math-standard-deviation-how-to-use… Sent from the Boost - Users mailing list archive at Nabble.com.

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interrupt a blocking stream read
by Chris Stankevitz 17 Aug '12

17 Aug '12

I am attempting to interrupt a blocking stream read. The below code doesn't work since std::istream::read is not a valid boost thread interruption point. Can someone recommend a way to get something like this work work, preferably using boost's cross-platform constructs? Thank you, Chris === void f() { try { char c[999999999]; cin.read(c, 999999999); } catch (boost::thread_interrupted) { } } int main() { boost::thread t(f); f.interrupt(); f.join() return 0; }

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[chrono] Issues with _ITERATOR_DEBUG_LEVEL
by Christian Henning 17 Aug '12

17 Aug '12

Hi there, compiling with the latest trunk version gives me the following linker error with the chrono lib: libboost_chrono-vc100-mt-1_51.lib(chrono.obj) : error LNK2038: mismatch detected for '_ITERATOR_DEBUG_LEVEL': value '0' doesn't match value '2' in Factory.obj Usually the solution is to recompile the lib with _ITERATOR_DEBUG_LEVEL=2 but the problem preservers. Can someone tell what wrong with compiling boost with: bjam -j8 --toolset=msvc --without-mpi variant=debug link=static runtime-link=shared define=_CRT_NONSTDC_NO_DEPRECATE define=_CRT_SECURE_NO_DEPRECATE define=_SCL_SECURE_NO_DEPRECATE define="_ITERATOR_DEBUG_LEVEL=2" stage I mean, is the define="_ITERATOR_DEBUG_LEVEL=2" syntactically correct? Thanks, Christian

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