November 2007 - Boost-users

[vector_property_map] vector size ?
by Jairo19＠interhosting.us 20 Nov '07

20 Nov '07

1 0

Re: [Boost-users] [boost] C++ Performance
by Maik Beckmann 20 Nov '07

20 Nov '07

Forwarded to boost-users... Am Dienstag 20 November 2007 16:24:42 schrieb nisha kannookadan: > Hi everybody > > Im a quite new boost user and I wonder, why C++ Program is so slow. > > I wrote a program, and I have the same program in Matlab, > I expected that my C++ version is much faster, but its not. > > I use matrices, vectors, matrix- and vector proxies. Do some > solving and compute calculations with prod, element_div, etc.. > > Is boost in general slower than matlab, should I use something > else? > > Id be real happy about any help. > > Regards > Nisha K > _________________________________________________________________ > Explore the seven wonders of the world > http://search.msn.com/results.aspx?q=7+wonders+world&mkt=en-US&form=QBRE > _______________________________________________ > Unsubscribe & other changes: > http://lists.boost.org/mailman/listinfo.cgi/boost

2 2

Re: [Boost-users] [filesystem] List all drive letters
by arno.schaefer＠sqs.de 20 Nov '07

20 Nov '07

> No, that's not currently possible. What is then the best way, to find all windows roots with the current version? Have you some example code? --Arno

2 1

Problem in using Transitive_closure on Linux
by abhishek.v＠tcs.com 20 Nov '07

20 Nov '07

Hi.. I m able to run transitive_closure on my windows machine but the same program gives me the following error on Linux machine what can be the reason for this .. /usr/include/boost/graph/depth_first_search.hpp: In function âvoid boost::depth_first_search(const VertexListGraph&, const boost::bgl_named_params<P, T, R>&) [with VertexListGraph = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >, P = boost::topo_sort_visitor<std::back_insert_iterator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >, T = boost::graph_visitor_t, R = boost::bgl_named_params<boost::identity_property_map, boost::vertex_index_t, boost::no_property>]â: /usr/include/boost/graph/topological_sort.hpp:64: instantiated from âvoid boost::topological_sort(VertexListGraph&, OutputIterator, const boost::bgl_named_params<P, T, R>&) [with VertexListGraph = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >, OutputIterator = std::back_insert_iterator<std::vector<long unsigned int, std::allocator<long unsigned int> > >, P = boost::identity_property_map, T = boost::vertex_index_t, R = boost::no_property]â /usr/include/boost/graph/transitive_closure.hpp:120: instantiated from âvoid boost::transitive_closure(const Graph&, GraphTC&, G_to_TC_VertexMap, VertexIndexMap) [with Graph = boost::adjacency_list<boost::setS, boost::vecS, boost::bidirectionalS, boost::property<boost::vertex_name_t, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::no_property>, boost::property<boost::edge_weight_t, int, boost::no_property>, boost::no_property, boost::listS>, GraphTC = boost::adjacency_list<boost::setS, boost::vecS, boost::bidirectionalS, boost::property<boost::vertex_name_t, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::no_property>, boost::property<boost::edge_weight_t, int, boost::no_property>, boost::no_property, boost::listS>, G_to_TC_VertexMap = boost::iterator_property_map<long unsigned int*, boost::vec_adj_list_vertex_id_map<boost::property<boost::vertex_name_t, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::no_property>, long unsigned int>, long unsigned int, long unsigned int&>, VertexIndexMap = boost::vec_adj_list_vertex_id_map<boost::property<boost::vertex_name_t, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::no_property>, long unsigned int>]â /usr/include/boost/graph/transitive_closure.hpp:263: instantiated from âvoid boost::transitive_closure(const Graph&, GraphTC&) [with Graph = Graph, GraphTC = Graph]â sample_main.cpp:121: instantiated from here /usr/include/boost/graph/depth_first_search.hpp:324: error: no matching function for call to âvertices(const std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >&)â //Pseudo Code on which it is failing /... Graph TC; transitive_closure(Original_graph, TC); ...// Kindly help..... Thanks Abhishek Vyas Tata Consultancy Services Mailto: abhishek.v(a)tcs.com Website: http://www.tcs.com ____________________________________________ Experience certainty. IT Services Business Solutions Outsourcing ____________________________________________ =====-----=====-----===== Notice: The information contained in this e-mail message and/or attachments to it may contain confidential or privileged information. If you are not the intended recipient, any dissemination, use, review, distribution, printing or copying of the information contained in this e-mail message and/or attachments to it are strictly prohibited. If you have received this communication in error, please notify us by reply e-mail or telephone and immediately and permanently delete the message and any attachments. Thank you

2 3

Need help with boost parameter library, multiple deduced defaults.
by StephQ 20 Nov '07

20 Nov '07

I am currently working on a mathematical library for the simulation of stochastic processes. I am a researcher in Statistics, hence my limited skills in c++ programming :) Let me introduce the framework briefly. The part of the library I am interested with is very similar to the boost random library. I need to implement it because I need to extend some functionality and I am not confident in modifying the boost random library to extend its behaviour (too complicated for me :P). We have (lazy syntax): PseudoRng<TImpl> //A particular pseduo random number generator QuasiRng<TImpl> // A particualr quasi random number generator GaussianDistribution // A particular statistical distribution Sampler<GaussianDistribution> // The interface (for other components of the library) of a sampler of random numbers distributed as a GaussianDistribution Then I consider: template < class TGenerator, class TDistribution, typename TDistribution::variate_t (TDistribution::*algorithm)( const TGenerator& ) const = &TDistribution::sample_default > class VariateSampler : public Sampler<TDistribution> { ... } Here TGenerator can be PseudoRng<TImpl> or QuasiRng<TImpl>, TDistribution can be GaussianDistribution and the pointer to member function algorithm select the algorithm used to sample. While constructing VariateSampler I would like to: 1) Automatically deduce the type of TGenerator and TDistribution 2) Automatically select a different default for algorithm, for particular TDistribution (like GaussianDistribution,PoissonDistribution....) depending on the fact that TGenerator is of type PseudoRng<TImpl> or QuasiRng<Timpl>. So for every TDistribution two different defaults for algorithm. I think that boost parameter should solve my problem, but I am quite confused about how to implement it, expecially the second point. Could you help me with the basic steps I need to consider? Thank you very much in advance. Regards StephQ

2 2

[graph] inheriting from adjacency_list
by Krishna Roskin 20 Nov '07

20 Nov '07

Hey all, I've been having some problems inheriting from adjacency_list. My code is real simple: ---------- 8>< ---------- #include<iostream> #include<string> #include<boost/graph/adjacency_list.hpp> using namespace boost; class Weighted : public adjacency_list<vecS, vecS, bidirectionalS, property<vertex_distance_t, double>, no_property, no_property> { }; int main(int argc, char* argv[]) { Weighted m; property_map<Weighted, vertex_distance_t>::type pmap = get(vertex_distance, m); return 0; } ---------- 8>< ---------- The error is: main.cpp: In function ‘int main(int, char**)’: main.cpp:16: error: conversion from ‘boost ::vec_adj_list_vertex_property_map<boost::adjacency_list<boost::vecS, boost::vecS, boost::bidirectionalS, boost::property<boost::vertex_distance_t, double, boost::no_property>, boost::no_property, boost::no_property, boost::listS>, boost::adjacency_list<boost::vecS, boost::vecS, boost::bidirectionalS, boost::property<boost::vertex_distance_t, double, boost::no_property>, boost::no_property, boost::no_property, boost::listS>*, double, double&, boost::vertex_distance_t>’ to non-scalar type ‘boost::vec_adj_list_vertex_property_map<Weighted, Weighted*, double, double&, boost::vertex_distance_t>’ requested make: *** [main.o] Error 1 Is there some reason that this won't work? Is it a bug? If I try to get property_maps for edge properties, I don't have problems. Any help greatly appreciated, -krish -- Krishna Roskin Center for Biomolecular Science and Engineering, UC Santa Cruz mailto:krish@soe.ucsc.edu http://www.soe.ucsc.edu/~krish/

1 0

enable_if on operators
by Robert Dailey 19 Nov '07

19 Nov '07

Hi, Right now I'm trying to overload the [] twice, however after compilation is done only one of the overloads will actually exist at runtime: template< unsigned int t_number > struct foo { t_type data[10]; t_type& operator[] ( unsigned int index ) { return data[index]; } }; In the structure above, I have only shown 1 array index operator just as an example. I want to define two overloads with the following conditions: 1) If t_number is equal to 1, enable_if will allow the first overload for the array operator. 2) If t_number is greater than 1, enable_if will allow the second overload for the array operator. Is there some sort of is_less_than or is_equal objects in boost I can use with enable_if for my operator overloads? Thanks.

2 1

base class should be explicitly initialized in the copy constructor
by Rock Star 19 Nov '07

19 Nov '07

Hello, I have a question regarding the warning that I get when I compile a program using boost::ublas library. I have to say that I'm not really experienced programmer so I might be doing something really stupid... Anyway, I'm using WinXP with Mingw 3.4.5 and boost 1.34-1. I want to create a simple function that returns a vector. I have it written like this: ################################################################ > ====== file.h ====== < #include <boost/numeric/ublas/vector.hpp> typedef boost::numeric::ublas::vector<double> vec; vec testfunc (vec &v); > ====== file.cpp ====== < #include "file.h" vec testfunc (vec &v) { vec v1 = v/2; return v1; } #################################################################### When I try to compile, I get the following warning: base class `class boost::numeric::ublas::storage_array<boost::numeric::ublas::unbounded_array<double, std::allocator<double> > >' should be explicitly initialized in the copy constructor How can I get rid of this warning? Thank you very much for your answers.

1 0

Serialization - 'size_t' to 'std::streamsize' error
by Dave Nay 19 Nov '07

19 Nov '07

Ok....this is really confusing. I successfully created a small test project several months ago using the Boost Serialization library to serialize some binary data. I am now attempting to add binary serialization to a production project, and I receive a bunch of compiler warnings. I can still compile and execute the test application with no warnings or errors. I am using VS2005 with boost 1.34.1 I have included the first few compiler warnings below... 1>C:\Program Files\boost\boost_1_34_1\boost/archive/basic_binary_oprimitive.hpp(136) : warning C4267: 'argument' : conversion from 'size_t' to 'std::streamsize', possible loss of data 1> C:\Program Files\boost\boost_1_34_1\boost/archive/basic_binary_oprimitive.hpp(120) : while compiling class template member function 'void boost::archive::basic_binary_oprimitive<Archive,Elem,Tr>::save_binary(const void *,size_t)' 1> with 1> [ 1> Archive=boost::archive::binary_oarchive, 1> Elem=char, 1> Tr=std::char_traits<char> 1> ] 1> C:\Program Files\boost\boost_1_34_1\boost/archive/detail/oserializer.hpp(91) : see reference to function template instantiation 'void boost::archive::basic_binary_oprimitive<Archive,Elem,Tr>::save<T>(const T &)' being compiled 1> with 1> [ 1> Archive=boost::archive::binary_oarchive, 1> Elem=char, 1> Tr=std::char_traits<char>, 1> T=unsigned char 1> ] 1> C:\Program Files\boost\boost_1_34_1\boost/archive/detail/oserializer.hpp(244) : see reference to function template instantiation 'void boost::archive::save_access::save_primitive<Archive,T>(Archive &,const T &)' being compiled 1> with 1> [ 1> Archive=boost::archive::binary_oarchive, 1> T=unsigned char 1> ] Thanks, Dave -- Dave Nay CIVision, LLC

2 2

Setup for MinGW/EasyEclipse
by Chris Miller 19 Nov '07

19 Nov '07

I know this is rather menial to be asking for assistance on, but I'm stuck and don't want to proceed and make a mistake. I'm rather sick of messing up with simple library setup things, and want to get down and dirty with some code soon! So if you could be so kind as to help me understand what to do I'd really appreciate it. I've got to make Boost work on Microsoft Windows XP SP2, using the MinGW libraries that came with EasyEclipse C/C++. However, the getting started documentation on Boost.org only discusses how to make Boost work for MSVC, which doesn't help me all too much. If some kind person could help this tired programmer, I'd really appreciate it! I used Google, but I didn't find anything terribly definitive. If only Windows could be more like Linux, and all I'd have to do is something cool like wgm install boost-dev... but then it wouldn't be Windows, would it? Anyways, thanks in advance for any help anyone can render me!

4 4