June 2004 - Boost-users - lists.boost.org

Newbie question -- graph library example
by Tim Rowe 17 Jun '04

17 Jun '04

In the example examples/file_dependencies.cpp, I can't see what either of the typedefs for Color do: typedef property_map<Graph,vertex_color_t>::type Color; If I comment then out everything seems still to work. What are they there for? TIA, Regards, Tim

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[Tuple] broken for gcc-3.4.0
by Jürgen Hunold 17 Jun '04

17 Jun '04

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi ! After updating my cvs snapshot at 12.15 , the tuple library is broken for gcc 3.4.0. My own program stopped compiling and when going to libs/tuple/test and running bjam I get: In file included from /ive/hunold/packages/boost/boost/tuple/tuple.hpp:38, from ../../../libs/tuple/test/tuple_test_bench.cpp:19: /ive/hunold/packages/boost/boost/tuple/detail/tuple_basic.hpp: In function `typename boost::tuples::access_traits<typename boost::tuples::element<N, boost::tuples::cons<HT, TT> >::type>::non_const_type boost::tuples::get(boost::tuples::cons<HT, TT>&)': /ive/hunold/packages/boost/boost/tuple/detail/tuple_basic.hpp:212: error: `get_class' undeclared (first use this function) (full output of failing tests attached) So I think this is really something which gcc 3.4.0 does no handle. Yours, Jürgen - -- * Dipl.-Math. Jürgen Hunold ! Institut für Verkehrswesen, Eisenbahnbau * voice: ++49 511 762-2529 ! und -betrieb, Universität Hannover * fax : ++49 511 762-3001 ! Appelstrasse 9a, D-30167 Hannover * hunold(a)ive.uni-hannover.de ! www.ive.uni-hannover.de -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (GNU/Linux) iD8DBQFA0ZJ7ljbJ/LLrxrYRAhxCAJ9xnzG7bfPORsLVU9pjhD90RjP5CQCbBgL6 g154KH2PULNGi8pBFIDsiTM= =XvKx -----END PGP SIGNATURE-----

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boost::filesystem::path corruption
by Stuart Bingë 17 Jun '04

17 Jun '04

Hello all, I've recently started using some of the Boost libraries, one of which being boost::filesystem. I have however encountered a problem while using the library, which as far as I can tell is a bug. I'm not sure if anyone is aware of this problem, or if is not an issue with the library itself but rather with my configuration - in either case a description of the problem follows: Whenever I instantiate a boost::filesystem::path object and try to print out a text representation of the path using a method such as .string(), the path itself is printed out, however it looks as though the string is not terminated properly as a whole bunch of trailing garbage appears after the path. The following sample program produces the problem for me: #include <iostream> #include <boost/filesystem/path.hpp> int main(int c, char** v) { boost::filesystem::path testpath("test/path"); std::cout << testpath.native_file_string() << std::endl; return 0; } When I run this code I get output similar to the following: test/pathpÿÿÿÿtest/ÿÿÿÿdataÿÿÿÿpath... etc (a whole bunch of other random stuff like days of the week & month, as well as garbage character strings) Can anyone shed some light on this for me? I'm running boost version 1.31.0 on Gentoo Linux x86 (kernel 2.6.5-gentoo-r1) with GCC version 3.3.2, for anyone who is interested. Regards, Stuart Bingë

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limiting searches in BGL
by Jason Crosswhite 16 Jun '04

16 Jun '04

Hello, I am just starting to use the BGL, and have been beating my head upon a problem. I am needing to find an irregularly bounded set of points in three dimensional space. The points are within a convex hull and the graph edges are edges in a delaunay triangulation. I want to start at a node known to be on the hull, and crawl through the inside with either depth first or breadth first search. If you are on the hull, you would not allow the search to continue outside the hull. I thought of doing this with a simple visitor, and color the unwanted vertices black. However, from inside the scope of the visitor, I do not believe I can have access to the colors. Several ugly hacks come to mind, but I would like to know if there is an easy way of doing this first? -Jason Crosswhite

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Re: limiting searches in BGL
by Vladimir Prus 16 Jun '04

16 Jun '04

Hi Jason, > I am just starting to use the BGL, and have been beating my head upon a > problem. I am needing to find an irregularly bounded set of points in > three dimensional space. The points are within a convex hull and the > graph edges are edges in a delaunay triangulation. I want to start at a > node known to be on the hull, and crawl through the inside with either > depth first or breadth first search. If you are on the hull, you would > not allow the search to continue outside the hull. I think you might want to use 'TerminatorFunc' argument to depth_first_visit. That's a functor which returns true if the search should not continue after a certain vertex. - Volodya

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dynamic boost::array and performance/size of STL vector
by Bo Peng 15 Jun '04

15 Jun '04

Dear list, I frequently need to use arrays with undetermined (at compile time) but constant (user specify size) size. I.e., I need something like boost::array<int> arr(5); without arr.insert etc, rather than boost::array<int,5> arr; which only accept constant array length. Of course I can use 'vector<int> arr(5)' in this case but I am worry about the performance and size overhead, specifically: 1. How is size() implemented in vector<>? I am concerned with this function since icc (intel c++ compiler) can not vectorize 'for(i=0;i<arr.size();i++)' unless arr.size() is an inlined reference to a variable. 2.Since I will have a lot of such arrays, I would also like to know how many additional variables vector<int> keeps. I.e. exactly how big is vector<int> arr(5)? It might be trivial to copy boost::array and add constructor/destructor but I do not want to re-invent the wheel. Thanks. Bo

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RE: [Boost-users] Regex lookahead/lookbehind
by James Gunn 15 Jun '04

15 Jun '04

*** Before acting on this e-mail or opening any attachment you are advised to read the disclaimer at the end of this e-mail *** Hi John, > -----Original Message----- > From: John Maddock [mailto:john@johnmaddock.co.uk] > Sent: 15 June 2004 12:40 > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] Regex lookahead/lookbehind > > > > Hi all, > > > > Is it possible to do lookahead and/or lookbehind within > boost::regex? > > Lookahead is supported at present, lookbehind will be in the > next revision (currently in cvs in the branch called regex5). > > John. Thanks for the quick response. In the end I managed to solve my current problem without needing lookahead or lookbehind. I used your (earlier) advice of checking for word boundaries at the beginning and end of my regular expression and this has helped loads! The latest version of my postcode validation expression is shown below: (\bGIR\s0AA\b)| (\b[^QVX\W0-9][^IJZ\W\s]([0-9]{1,2}?|[ABCDEFGHJKSTUW0-9]?|[0-9][ABEHMNPRVWXY ]?) \s+\d[^CIKMOV]{2}\b) I'm certain that the expression could be made simpler and that it could also be made more efficient but I'm not sure where. Cheers, James ********************************************************************** Please note: This e-mail and its attachments contain only the opinions of the sender and do not necessarily reflect the policy(s) of the communisis group in general. Employees of the communisis group are required not to make any defamatory statements and not to infringe or authorise any infringement of copyright or any other legal right by e-mail. Any such communication is therefore outside the scope of employment of the individual concerned. The communisis group will not accept any liability in respect of such a communication. Confidentiality: This e-mail and any attachments, together with their contents, are confidential unless otherwise explicitly stated in writing by the sender of this e-mail and are for the intended recipient only. If they have come to you in error you must not take any action in respect of them, which includes but is not limited to reproducing, sending or storing them, other than to notifying the sender immediately of the mistake, and deleting the e-mail, any attachments and any reproductions made by replying to it. Viruses: This e-mail and any attachments have been scanned for viruses but we cannot guarantee that they are virus free. The recipient should check this e-mail and any attachments for viruses. The communisis group accepts no responsibility for any damage caused by any virus transmitted by this e-mail or any of its attachments. In the event of any unauthorised copying or forwarding, the recipient will be required to indemnify the communisis group against any claim for loss or damage caused by any viruses or otherwise. ********************************************************************** ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________

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Regex lookahead/lookbehind
by James Gunn 15 Jun '04

15 Jun '04

*** Before acting on this e-mail or opening any attachment you are advised to read the disclaimer at the end of this e-mail *** Hi all, Is it possible to do lookahead and/or lookbehind within boost::regex? Thanks in advance James Gunn Software Developer --LongSig Computer Bureau Communisis DM Manston Lane Crossgates Leeds LS15 8AH Telephone +44 (0)113 225 5306 Fax +44 (0)113 225 5921 Email James.Gunn(a)communisis-dm.co.uk ********************************************************************** Please note: This e-mail and its attachments contain only the opinions of the sender and do not necessarily reflect the policy(s) of the communisis group in general. Employees of the communisis group are required not to make any defamatory statements and not to infringe or authorise any infringement of copyright or any other legal right by e-mail. Any such communication is therefore outside the scope of employment of the individual concerned. The communisis group will not accept any liability in respect of such a communication. Confidentiality: This e-mail and any attachments, together with their contents, are confidential unless otherwise explicitly stated in writing by the sender of this e-mail and are for the intended recipient only. If they have come to you in error you must not take any action in respect of them, which includes but is not limited to reproducing, sending or storing them, other than to notifying the sender immediately of the mistake, and deleting the e-mail, any attachments and any reproductions made by replying to it. Viruses: This e-mail and any attachments have been scanned for viruses but we cannot guarantee that they are virus free. The recipient should check this e-mail and any attachments for viruses. The communisis group accepts no responsibility for any damage caused by any virus transmitted by this e-mail or any of its attachments. In the event of any unauthorised copying or forwarding, the recipient will be required to indemnify the communisis group against any claim for loss or damage caused by any viruses or otherwise. ********************************************************************** ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________

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Regex failing to match postcodes
by James Gunn 15 Jun '04

15 Jun '04

*** Before acting on this e-mail or opening any attachment you are advised to read the disclaimer at the end of this e-mail *** Hi all, I'm having some difficulty getting my regular expression working. Basically, I need to make sure that a UK postcode is valid. The postcode that is passed to my function sometimes has extra things with it such as: Wakefield, WF1 3RD Shrewsbury SY2 5PT Shropshire It now seems to be failing to find the postcode in the above examples. Also, when I pass my function a postcode that I know is invalid, such as JG2 7L5 it matches it as G2 7L5 instead of failing to do the match. The regular expression I'm using is below: (?:(?:(^|\s)+ A[BL]|B[ABDHLNRST]?| C[ABFHMORTVW]|D[ADEGHLNTY]|E[CHNX]?|F[KY]|G[LUY]?| H[ADGPRSUX]|I[GMPV]|JE|K[ATWY]|L[ADELNSU]?|M[EKL]?| N[EGNPRW]?|O[LX]|P[AEHLOR]|R[GHM]|S[AEGKLMNOPRSTWY]?| T[0ADFNQRSW]|UB|W[ACDFNRSV]?|YO|ZE) \d(?:\d|[A-Z])?\s+\d[A-Z]{2}($|\s)+) Can anyone tell me whats wrong with my expression? BTW I'm using boost 1.31.0 on VC++ 7.1, Windows XP. James Gunn Software Developer --LongSig Computer Bureau Communisis DM Manston Lane Crossgates Leeds LS15 8AH Telephone +44 (0)113 225 5306 Fax +44 (0)113 225 5921 Email James.Gunn(a)communisis-dm.co.uk ********************************************************************** Please note: This e-mail and its attachments contain only the opinions of the sender and do not necessarily reflect the policy(s) of the communisis group in general. Employees of the communisis group are required not to make any defamatory statements and not to infringe or authorise any infringement of copyright or any other legal right by e-mail. Any such communication is therefore outside the scope of employment of the individual concerned. The communisis group will not accept any liability in respect of such a communication. Confidentiality: This e-mail and any attachments, together with their contents, are confidential unless otherwise explicitly stated in writing by the sender of this e-mail and are for the intended recipient only. If they have come to you in error you must not take any action in respect of them, which includes but is not limited to reproducing, sending or storing them, other than to notifying the sender immediately of the mistake, and deleting the e-mail, any attachments and any reproductions made by replying to it. Viruses: This e-mail and any attachments have been scanned for viruses but we cannot guarantee that they are virus free. The recipient should check this e-mail and any attachments for viruses. The communisis group accepts no responsibility for any damage caused by any virus transmitted by this e-mail or any of its attachments. In the event of any unauthorised copying or forwarding, the recipient will be required to indemnify the communisis group against any claim for loss or damage caused by any viruses or otherwise. ********************************************************************** ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________

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[uBLAS] Compilation problem with VC 7.1
by kjfh kjnk 15 Jun '04

15 Jun '04

Hi, This simple code creates 2 ublas vector and computes the inner_product. It does not compile with VC 7.1: --------------------------------------------------- #include <iostream> #include <string> #include <boost/concept_check.hpp> #include <boost/numeric/ublas/matrix.hpp> namespace ublas = boost::numeric::ublas; int main(int argc, char **argv) { ublas::vector<unsigned short> toto(3); ublas::vector<double> tata(3); double titi = ublas::inner_prod(toto, tata); return 0; } --------------------------------------------------- Here is the compilation: *************************************************** C:\Temp\ublas>cl -I"C:\Program Files\boost_1_31_0" /EHsc ublas-test.cpp Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 13.10.3052 for 80x86 Copyright (C) Microsoft Corporation 1984-2002. All rights reserved. ublas-test.cpp ublas-test.cpp(12) : error C2440: 'initializing' : cannot convert from 'boost::numeric::ublas::vector_scalar_binary_traits<E1,E2,F>::result_type' to 'double' with [ E1=boost::numeric::ublas::vector<unsigned short>, E2=boost::numeric::ublas::vector<double>, F=boost::numeric::ublas::vector_inner_prod<unsigned short,double,boost::mpl::if_c<false,unsigned short,boost::numeric::ublas::promote_traits<unsigned short,double>::builtin_promote_type>::type> ] No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called C:\Temp\ublas> **************************************************** It compiles well with with VC 6.0, but the result is not good... (with a proper initialisation) Anybody has an idea ? JD ___________________________________________________________ALL-NEW Yahoo! Messenger - sooooo many all-new ways to express yourself http://uk.messenger.yahoo.com

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