January 2006 - Boost-users - lists.boost.org

Profiling Boost Graph Library with gprof
by Dave 10 Jan '06

10 Jan '06

Hello All, I have been trying to profile a few graph algorithms written using Boost Graph Library. I am using gprof for profiling. My graph has 100 vertices. It takes more than 10 minutes to compile, I suspect it is because of the size of the graph. The profile does not show any details though. It only shows the amount of time spent by the profiler. What am I doing wrong? Any help is greatly appreciated! Thanks. __________________________________________ Yahoo! DSL Something to write home about. Just $16.99/mo. or less. dsl.yahoo.com

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Understanding Boost.Mpl Fold Algorithm
by Eduardo Bezerra 10 Jan '06

10 Jan '06

Hi, I'm having a hard time trying to understand what the placeholders _1 and _2 mean in the context of the mpl::fold algorithm. >From the Boost.Mpl Reference manual: typedef vector<long,float,short,double,float,long,long double> types; typedef fold< types , int_<0> , if_< is_float<_2>,next<_1>,_1 > >::type number_of_floats; BOOST_MPL_ASSERT_RELATION( number_of_floats::value, ==, 4 ); Could someone give me some help on this ? Best regards, Eduardo

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Is there a StringBuffer equivalent in Boost library?
by ying lcs 10 Jan '06

10 Jan '06

Is there a StringBuffer equivalent in Boost library? If not, what is the most efficient way to append string? Thank you. __________________________________________ Yahoo! DSL Something to write home about. Just $16.99/mo. or less. dsl.yahoo.com

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Bind signals together
by Will 10 Jan '06

10 Jan '06

Hi, I'm looking for a general technique for binding signals with varying signatures together. Obviously i can create custom functions for any specific case, but i'm wondering if boost::bind could be used to help out here? i.e. boost::signal1<void, const char *> sig1; boost::signal0<void> sig2; void bing() { std::cout << "bing" << std::endl; } // connect sig1 to sig2 such that calling sig1 will invoke sig2 // ... <- how do i do this? // connect sig2 to some function sig2.connect(&bing); // call the signal sig1("some string"); Thanks in advance - Will

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any Boost library for unit testing C++ code
by ying lcs 09 Jan '06

09 Jan '06

Hi, Is there any Boost library for unit testing C++ code? If not, can anyone please recommend any good library for unit testing C+++ code? Thank you. __________________________________________ Yahoo! DSL Something to write home about. Just $16.99/mo. or less. dsl.yahoo.com

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boost::thread problem on 1.33.1
by Brian Plummer 09 Jan '06

09 Jan '06

The following simple program seg faults. (I have boiled it down to the bare essentials to product the fault: ================================================================== #include <boost/thread.hpp> void * MMULT2(void); void * MMULT2CalcMaster(void); int main(void) { MMULT2(); } class MMULT2ThreadClass { void calculate(void) {} public : MMULT2ThreadClass() {} void operator ()() { calculate(); } }; void * MMULT2CalcMaster(void) { int numThreads = 2; boost::thread_group threads; for (int i = 0; i < numThreads; ++i) threads.create_thread(MMULT2ThreadClass()); threads.join_all(); } void * MMULT2(void) { return MMULT2CalcMaster(); } ================================================================== Here is the compile line: cd /SDE/common/src/lib/PSF/PSFWorkbook/testing/BoostThreadProblem/ make clean run DEBUG=YES /bin/rm -rf DO/LINUX_X86_GCC3.4.5/debug/BoostThreadProblem.o /SDE/common/bin/LINUX_X86_GCC3.4.5/debug/BoostThreadProblem *.o *.i Templates.DB gcc -I. -I/SDE/common/include -I/usr/java/jdk1.3.1_01/include -I/usr/java/jdk1.3.1_01/include/linux -I/opt/sybase-11.9.2/include -c -g -DDEBUG -D_TRACE -DLITTLEENDIAN=1 -DDBG=1 -DDEVL=1 -DDBGPROP -D_UNIX -DNEWPROPS -DBRP_LINUXINTEL -DBRP_LITTLE_ENDIAN BoostThreadProblem.cpp -o DO/LINUX_X86_GCC3.4.5/debug/BoostThreadProblem.o gcc DO/LINUX_X86_GCC3.4.5/debug/BoostThreadProblem.o -L/usr/local/lib -L/usr/lib -L/SDE/COTS/Boost/boost_1_33_1/bin/boost/libs/thread/build/libboost_thread.a/gcc/release/threading-multi -lboost_thread-gcc-mt-d-1_33_1 -o /SDE/common/bin/LINUX_X86_GCC3.4.5/debug/BoostThreadProblem /SDE/common/bin/LINUX_X86_GCC3.4.5/debug/BoostThreadProblem make: *** [run] Segmentation fault Compilation exited abnormally with code 2 at Wed Jan 4 17:12:11 ================================================================== I have tried using the -pthread and -D_REENTRANT compile flags with no luck. I had previously used the code that this example is based on, without any problems under 1.30.0 (and not using the -pthread and -D_REENTRANT flags). I feel I've got to be missing something very basic associated with building and using the Thread library. At this point I'm a bit stumped. Also, I noticed the following. bjam -sTOOLS=gcc in the build directory only builds the mt_d version of the library and not the release version. I don't remember needing to do anything special to get both versions built. Additionally, I'm not having any of these problems with the same code on WIN32 with Visual Studio 2003. Thanks in advance, Brian

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[Parameter] Documentation opinions
by Thomas Matelich 09 Jan '06

09 Jan '06

Parameter seems perfect for some code I'm writing now, so I thought I'd give it a look. The organization of the documentation is definitely not oriented to the type of library user I am (skim tutorial, quick copy/paste of example, then hack with reference docs). I have two requests that would have given me less headaches. 1) Provide complete source for the examples at 3 phases. Say a .cpp covering the topics learned so far at the end of each 2.x section. Going and looking at the test code, I did find tutorial, though I was disappointed to find it had only the first minimal example, and the other test code is built around smaller/simpler problems 2) Move the reference doc link to the top. I totally missed it until I hit Konqueror's Up navigation button and saw the rst in http://www.boost.org/libs/parameter/doc/. Thanks for listening. Tom PS Please don't ask for patches, this is a suggestion, I don't care if you do it or not. I know Dave's a stickler for good docs, so I'm giving some feedback.

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user defined seed
by Giulio Veronesi 09 Jan '06

09 Jan '06

Hi all, I've a problem with random number generator. Let us consider the following code fragment: long int s = 123456; mt19937 rnd_gen(s); When I try to compile it I get the following error message: /home/mpalesi/WORK/TOOLS/BGL/current/boost/random/mersenne_twister.hpp: In member function `void boost::random::mersenne_twister<UIntType, w, n, m, r, a, u, s, b, t, c, l, val>::seed(Generator&) [with Generator = long int, UIntType = uint32_t, int w = 32, int n = 624, int m = 397, int r = 31, UIntType a = 09908b0df, int u = 11, int s = 7, UIntType b = 09d2c5680, int t = 15, UIntType c = 0efc60000, int l = 18, UIntType val = 0c77666de]': /home/mpalesi/WORK/TOOLS/BGL/current/boost/random/mersenne_twister.hpp:67: instantiated from `boost::random::mersenne_twister<UIntType, w, n, m, r, a, u, s, b, t, c, l, val>::mersenne_twister(Generator&) [with Generator = long int, UIntType = uint32_t, int w = 32, int n = 624, int m = 397, int r = 31, UIntType a = 09908b0df, int u = 11, int s = 7, UIntType b = 09d2c5680, int t = 15, UIntType c = 0efc60000, int l = 18, UIntType val = 0c77666de]' src/apsra_mesh.cpp:253: instantiated from here /home/mpalesi/WORK/TOOLS/BGL/current/boost/random/mersenne_twister.hpp:103: error: ` gen' cannot be used as a function make: *** [obj/apsra_mesh.o] Error 1 The src/apsra_mesh.cpp:253 is the row "mt19937 rnd_gen(s);" I've no problem if I try to compile: mt19937 rnd_gen(123456); Please, could you help me to resolve this problem? Best regards, Giulio Chiacchiera con i tuoi amici in tempo reale! http://it.yahoo.com/mail_it/foot/*http://it.messenger.yahoo.com

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Field of record as boost::any
by Mateusz Łoskot 09 Jan '06

09 Jan '06

Hi, Is boost::any suitable to use it as a type of field of record? Record is a set of fields. Every field may store value of different type: int, double, char*. Usually, in this case I'd use union of int,double and char*. But I'd like to solve it a better way, more C++ than C. So, would you recommend boost::any as a type of field value? Cheers -- Mateusz Łoskot http://mateusz.loskot.net

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Is boost::filesystem::path unable to deal with hidden unix dircetories?
by Hendrik Belitz 09 Jan '06

09 Jan '06

Dear boost users and developers, I just encountered a minor problem in boost::filesystem::path which seems to be unable to deal with hidden unix directories ( == names preceeded by an dot '.' character ). Is there any way to generate a valid path object for paths like "/foo/.bar"? Trying to create such an object from a C++ string results in an exception getting thrown. ------------------------------------------------------------------------------------- Dipl.-Inform. Hendrik Belitz Central Institute of Electronics / Zentralinstitut für Elektronik Multimodal image processing workgroup / AG Multimodale Bildverarbeitung Research Center Juelich / Forschungszentrum Jülich GmbH D-52428 Jülich, Germany Tel.: (++49)2461 61 8701 Fax: (++49)2461 61 3990 email: h.belitz(a)fz-juelich.de ggp-key available via http://pgpkeys.pca.dfn.de

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