May 2011 - Boost-users - lists.preview.boost.org

offlist - Re: [iterator] Problems with iterator_facade and const-qualification
by Neil Groves 24 May '12

24 May '12

On Sat, May 7, 2011 at 5:52 PM, Dave Abrahams <dave(a)boostpro.com> wrote: > On Fri, May 6, 2011 at 1:51 PM, Evan Driscoll <driscoll(a)cs.wisc.edu> > wrote: > > On 05/06/2011 11:59 AM, Jeff Flinn wrote: > >> > >> You might google any_iterator, and see how other authors have addressed > >> similar problems. > > > > Great! I tried to find someone who had done something similar, figuring I > > couldn't have been the first, but all the search terms I tried were too > > generic. > > > > Thanks, > > Evan > > You can find one in the ASL that's built on iterator_facade. > http://stlab.adobe.com/classadobe_1_1any__iterator.html > > The underlying Boost.Range implementation implements an any_iterator that I believe to be similar to the one in ASL in terms of functionality. I believe that the small-buffer optimization implementation is superior to forcing the definition of a closed-set of possible type as suggested in a TODO within the ASL documentation. During my performance testing I had considerably superior performance than the ASL implementation. I wondered if you disliked my implementation, or had any feedback. Additionally I wondered what you thought about moving the Boost.Range internal any_iterator implementation into Boost.Iterator. I can't honestly imagine a good use-case for using any_iterator in preference to any_range, hence I haven't suggested this previously. This could easily be due to my lack of imagination! Can you think of a time when using an any_iterator on any interface would be superior to using an any_range? Your opinions and guidance would be much appreciated. HTH, > > -- > Dave Abrahams > BoostPro Computing > http://www.boostpro.com Regards, Neil Groves

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Recommended mock framework to use with Boost?
by doug livesey 15 Mar '12

15 Mar '12

Hi -- I'm trying to learn to develop properly with C++ and Boost, and to that end am learning along with Boost.Test, as I'm a BDD coder in another language (Ruby) in my day job. I'm at the point, now, where my tests could really benefit from a mocking framework. There doesn't appear to be one in Boost (not documented, at least), so I wondered if anyone on the list could recommend a mocking framework that they use that works well with Boost.Test? Any and all advice gratefully received, Doug.

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multi-array and pdes
by petros 07 Nov '11

07 Nov '11

Hi, These can very well be very naive questions, since I am relatively new to this - apologies..: I am trying to write a pde solver for a 3D problem. Multi-array seems like a very natural choice for a data structure to store the functtion values. The method I am trying to use is operrator splitting. This amounts to solving a tridiagonal system for each dimension in sequence. Suppose then that I have a MA( M, N, L ): It is highly desirable to maintain this xyz (let's call it) "logical" system of reference since incorporation of boundary conditions and stencil calculations would be conceptually straightforward -otherwise very complicated. The idea being that, I would then have the tridiagonal opertator ( and rhs) in the "rotated" system and all other calculations in the "logical" one. Therefore, I need some fascility to rotate my MA, from the xyz to yzx etc (cyclically). Is there functionality ( as a view to the data ) that would allow me to do this off-the-shelve? Also, a couple of other points: -If I wanted to use views to subgrids, in parallelized calculations, are there memory allocations that happen under the hood for which I should worry (for performance)? -Is a one dimensional MA usable? -Are there adapters between 2D MAs and uBlas matrices? Thank you very much for your help in advance! P-

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[BGL] Distributed adiacency_list memory allocation
by Cosimo Calabrese 27 Sep '11

27 Sep '11

Hi to all, I'm working on WinXP, VS2010, Boost 1.46.1. I've writed this short program: //---------------------------------- #include <boost/graph/use_mpi.hpp> #include <boost/graph/distributed/mpi_process_group.hpp> #include <boost/graph/distributed/adjacency_list.hpp> using boost::graph::distributed::mpi_process_group; typedef boost::property<boost::vertex_distance_t, long, boost::property<boost::vertex_name_t, std::string > > vertex_prop; typedef boost::property<boost::edge_weight_t, long > edge_prop; typedef boost::adjacency_list< boost::vecS, boost::distributedS<mpi_process_group, boost::vecS>, boost::directedS, vertex_prop, edge_prop > Graph; typedef boost::graph_traits<Graph>::edge_descriptor EdgeDescriptor; typedef boost::graph_traits<Graph>::vertex_descriptor VertexDescriptor; int main(int argc, char* argv[]) { boost::mpi::environment env(argc,argv); Graph g( 10 ); return 0; } //---------------------------------- When I launch it, every process allocates about 1 GB of memory. Why it allocates all that memory? Is it normal? Is there any tuning to the PBGL framework that I must made? I use it on a 2-core machine, and the command that I use is: mpiexec -n 2 .\test.exe I've tried with openMPI 1.4.3 and Microsoft HPC Pack 2008, but it seems irrilevant. Thanks in advance, Cosimo Calabrese.

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[build] cannot specify different version of gcc
by Brodie Thiesfield 25 Aug '11

25 Aug '11

Hi, I'm trying to build boost on CentOS 5.5 using the /usr/bin/gcc44 compiler and I'm running into difficulties with documentation not fitting reality. How do I make this work? What I've tried... Note: I've removed /usr/bin/gcc and /usr/bin/g++ to force errors when gcc44 and g++44 are not used. Using ./bootstrap.sh Building Boost.Jam with toolset ... tools/jam/src/### ### No toolset specified. Please use --toolset option. Setting CC=/usr/bin/gcc44 and CXX=/usr/bin/g++44 (note that this won't work if gcc and g++ exist because then it will default to the gcc toolkit and not the gcc-4.4 toolkit that I want). This builds a number of things (looking at the bootstrap.log) but still gives the following error. Ignoring the error and calling ./bjam then fails. Building Boost.Jam with toolset ... tools/jam/src/### ### No toolset specified. Please use --toolset option. Using ./bootstrap.sh --toolset=gcc gives an error: unrecognized option: --toolset=gcc Using ./bootstrap.sh --with-toolset=gcc gives an error: Building Boost.Jam with toolset gcc... Failed to build Boost.Jam -> bootstrap.log shows that it is trying to build with gcc, which doesn't exist, therefore error. Using ./bootstrap.sh --with-toolset=gcc-4.4 gives an error: Building Boost.Jam with toolset gcc... Failed to build Boost.Jam -> bootstrap.log shows ### Unknown toolset: gcc-4.4 Creating ~/user-config.jam as: import toolset.using ; using gcc : 4.4 : g++44 ; export BOOST_USER_CONFIG=~/user-config.jam Then calling the same ./bootstrap.sh command lines above show no difference. How in the world do I get this thing to use /usr/bin/gcc44 and /usr/bin/g++44 to compile? I think that I'm going to have to create local links ./gcc -> /usr/bin/gcc44 and add the current directory to the path just to get this to build the way that I want it to. This seems crazy. Regards, Brodie

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MSVC Visualizers Update
by Filip Konvička 28 Jul '11

28 Jul '11

Hi all, I've just updated the Boost visualizers wiki page at https://svn.boost.org/trac/boost/wiki/DebuggerVisualizers I updated the visualizer for Boost.MultiIndex, which did not work since Boost 1.35. I also added new visualizers for Boost.DateTime (ptime and time_duration) and a simple boost::shared_ptr visualizer. The visualizers are available for checkout via SVN at https://svn.boost.org/svn/boost/sandbox/boost_docs/subprojects/DebuggerVisu… Cheers, Filip

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[multi-array] Extracting dimension information from a multi-array
by Ryan McConnehey 15 Jul '11

15 Jul '11

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[Python] Undefined symbol in extension library with python 3
by Vivek 17 Jun '11

17 Jun '11

I compiled and installed boost 1.46.1 from source recently using: $ ./bootstrap.sh --with-python-version=3.1 $ sudo ./bjam -j4 install I then created the following trivial python extension: #include <boost/python.hpp> struct mystruct { int i; }; BOOST_PYTHON_MODULE(test) { using namespace boost::python; class_<mystruct>("Mystruct") .def_readwrite("i", &mystruct::i) ; } and compiled and ran it, but got an undefined symbol error: $ g++ -shared question.cpp -I/usr/include/python3.1 -lboost_python3 -otest.so $ python3 Python 3.1.2 (release31-maint, Sep 17 2010, 20:34:23) [GCC 4.4.5] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> import test Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: ./test.so: undefined symbol: _ZN5boost6python6detail11init_moduleEPKcPFvvE ldd confirms the missing symbol: $ ldd -r test.so linux-gate.so.1 => (0x00221000) libboost_python3.so.1.46.1 => /usr/local/lib/libboost_python3.so.1.46.1 (0x00a3d000) libstdc++.so.6 => /usr/lib/libstdc++.so.6 (0x0022b000) libm.so.6 => /lib/libm.so.6 (0x00960000) libc.so.6 => /lib/libc.so.6 (0x00316000) libutil.so.1 => /lib/libutil.so.1 (0x004b8000) libpthread.so.0 => /lib/libpthread.so.0 (0x00cf2000) libdl.so.2 => /lib/libdl.so.2 (0x00be4000) librt.so.1 => /lib/librt.so.1 (0x005d3000) libgcc_s.so.1 => /lib/libgcc_s.so.1 (0x00489000) /lib/ld-linux.so.2 (0x00fd5000) undefined symbol: PyExc_ImportError (/usr/local/lib/libboost_python3.so.1.46.1) undefined symbol: PyProperty_Type (/usr/local/lib/libboost_python3.so.1.46.1) ... snip ... *undefined symbol: _ZN5boost6python6detail11init_moduleEPKcPFvvE (./test.so) * undefined symbol: _Py_NoneStruct (./test.so) undefined symbol: PyLong_FromLong (./test.so) undefined symbol: PyLong_Type (./test.so) However nm confirms that the symbol exists in /usr/local/lib/libboost_python3.so.1.46.1: $ nm /usr/local/lib/libboost_python3.so.1.46.1 | c++filt | grep init_module 00031a00 T boost::python::detail::init_module(PyModuleDef&, void (*)()) I've tried running ldconfig to update the library cache, as well as compiling the extension with -lpython3.1, but no luck. Ideas appreciated, Vivek

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[Boost Serialization] Problem serializing derived class declared in DLL
by kmdarkmaster 13 Jun '11

13 Jun '11

Dear Boost community, My problem is simple : I need to serialize a derived class (named Plugin) of a c++ class (named Base) in my main program. The derived class Plugin is declared in a DLL which is load explicitely during execution. I tried to use the macro BOOST_CLASS_EXPORT_GUID (as in the doc), this works perfectly if the derived class is in the main execution, but will give me an exception if the derived class is in the plugin DLL. Forgive me if the problem is too obvious, this is my first time using Boost and I'm still a big noob in c++. Here is my code : IN THE MAIN EXECUTION : Class Base (parent class) : Base.h : #pragma once; #include "boost\serialization\access.hpp" #include <boost\serialization\nvp.hpp> class Base { private: friend class boost::serialization::access; template void serialize(Archive & ar, const unsigned int version){} public: int a, b; Base(); virtual ~Base() { } virtual void func()= 0; // this is an abstract base class } Base.cpp: #include "StdAfx.h" #include "Base.h" Base::Base(){ a=0; b=0; } IN THE DLL (loaded explicitely) Class Plugin (Child Class) : Plugin.h: #pragma once #include "boost\serialization\access.hpp" #include <boost\serialization\nvp.hpp> #include "boost\serialization\export.hpp" #include "Base.h" class Plugin: public Base { private: friend class boost::serialization::access; template void serialize(Archive & ar, const unsigned int version){ ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(Base); ar & BOOST_SERIALIZATION_NVP(a); ar & BOOST_SERIALIZATION_NVP(b); } public: virtual void func(); }; BOOST_CLASS_EXPORT_GUID(Plugin, "Plugin") Plugin.cpp: #include "StdAfx.h" #include "Plugin.h" void Plugin::func(){ a= 5; b= 6; } THE MAIN FUNCTION (IN THE MAIN EXECUTION): ....................................... HINSTANCE hinst= LoadLibrary(L"monDLLdynamique.dll"); if (hinst) { CreatePlugin ctor= (CreatePlugin)GetProcAddress(hinst, "CreatePlugin"); Base *test= ctor(); std::ofstream ofs3("FichierPointeursDerivedDLL.xml"); { boost::archive::xml_oarchive oa(ofs3); oa << BOOST_SERIALIZATION_NVP(test); } ofs3.close(); delete test; // calls Plugin's dtor FreeLibrary(hinst); } ............................................ Any help will be very very appreciated !!! Thanks -- View this message in context: http://boost.2283326.n4.nabble.com/Boost-Serialization-Problem-serializing-… Sent from the Boost - Users mailing list archive at Nabble.com.

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Objective-C++ boost integration
by kelvSYC 10 Jun '11

10 Jun '11

I'm wondering if there is any effort either at boost or elsewhere to have a library that integrates the C++ libraries with those of Objective-C++ (or Cocoa, since it seems that most treat the two as synonymous) in a nice way - for example, a smart pointer for Objective-C classes (via something like boost::intrusive_ptr), STL iterators for Objective-C containers, C++ function object integration with Objective-C selectors, etc.

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