June 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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Boost.Generic sources?
by Nathan Ridge 05 Mar '12

05 Mar '12

I just read about the Boost.Generic library at https://github.com/boostcon/2011_presentations/raw/master/thu/Boost.Generic…. It looks amazing! I understand it's not fully complete, but are the sources available somewhere? Thanks, Nate.

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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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Compilation Error in Boost::unordered_detail::hash_table on boost 1_46_1
by Shinil Gangadharan 27 Sep '11

27 Sep '11

Hi, I am using Sun CC v5.9 compiler to compile boost 1_46_1. We are getting the following error. Is there a way to get around with this error? "/dvobs/a-ThirdParty/Boost/boost_1_46_1/boost/unordered/detail/table.hpp", line 595: Error: Could not find a match for boost::unordered_detail::hash_table<boost::unordered_detail::T>::find(const boost::unordered_detail::Key&, const boost::unordered_detail::Hash&, const boost::unordered_detail::Pred&) const. "/dvobs/a-ThirdParty/Boost/boost_1_46_1/boost/unordered/detail/table.hpp", line 595: Error: Too many args in template, from boost::unordered_detail::Hash on ignored. Regards, Shinil V.G.

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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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trouble with boost/random/poisson_distribution and large lambda
by Michael King 30 Aug '11

30 Aug '11

Hello, I am new to the boost mailing list, so I apologize before hand if this is not the appropriate forum for this question. I have been using boost/random recently and have encountered what appears to be a problem with poisson variate generators with large lambda values. The random values can't seem to get much higher than 800 regardless of what value lambda is. For example: #include<iostream> #include<iterator> #include<vector> #include<algorithm> #include<boost/random/poisson_distribution.hpp> #include<boost/random/variate_generator.hpp> #include<boost/random/mersenne_twister.hpp> using namespace boost; using namespace std; int main() { mt19937 gen; double lambda = 1000.; poisson_distribution<int, double> pois(lambda); variate_generator<mt19937&, poisson_distribution<int, double> > rpois(gen, pois); // generate 10 random poisson variables vector<double> sample(10); generate(sample.begin(), sample.end(), rpois); cout << "Simulating from Poisson Random Variable with lambda=" << lambda << endl; cout << "\nSample: "; copy(sample.begin(), sample.end(), ostream_iterator<int>(cout, " ")); cout << "\n\nShouldn't the numbers be a little closer to 1,000?" << endl; return 0; } Thanks, Mike

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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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