February 2009 - Boost-users - lists.preview.boost.org

[BGL] Properties in a set-based adjacency list
by Grzegorz Slodkowicz 13 Feb '09

13 Feb '09

Hello, How can I use an external property map with an adjacency list which uses a setS for the vertex list? I got property maps (with arrays as storage for the property values) working fine with a vecS adjacency list, but I can't seem to get them to work after changing the template to setS. I understand the reason is lack of automatic indexing, but don't know how to get around that. Using set/map for storage of property values would most convenient for me. On a similar note, perhaps it's possible to use a map to store the vertices, mapping ints to Vertex descriptors? (that was the original custom implementation of graph class which I'm porting to BGL). TIA, Greg

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asio::transfer_at_least strange behavior
by Timenkov Yuri 13 Feb '09

13 Feb '09

Hi Is transfer_at_least supposed to return success only if requested number of bytes transferred at once or at all? For example, I want to receive 800 bytes and put them into streambuf using transfer_at_least(800) as completion condition, but I receive 2 chunks of 400 bytes, therefore I never get a success, because transfer_at_least_t always wants more data. I know, there are may be some problems with handler copying, but the name of function is misleading, and may be should be documented. I'm using boost 1.37, may be something has changed in 1.38.

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compiling Boost with STLport
by Kevin Li 13 Feb '09

13 Feb '09

Hi, I have a question about compiling Boost 1.38.0 with STLport. According to the document of Boost.Build, we can do following things: (1)modifying user-config.jam to point directories about STLport; (2)adding stdlib=stlport to bjam command; Using this method,We can compile Boost 1.38.0 with STLport supported. There is a 'p' in the libraries' name. But, I had a problem today. I recompiled Boost without STLport and checked there isn't a 'p' in libraries' name. When I compiled my program there is a error: can't link to stlport.5.2.lib At the end, I took off STLport's path from $INCLUDE_PATH (at the first) and compiled Boost again. Then I compiled my program successful. So, I think if we put STLport's path to the first of $INCLUDE_PATH when compiling Boost. It will links STLport too, but there is a 'p' in the libraries' name. I need your help. PS: I use MSVC 8.0 on Windows XP. Sincerely -------------- Kevin Li 2009-02-13

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Re: [Boost-users] tuples with more than 10 template parameters.
by Mauricio Gomes 12 Feb '09

12 Feb '09

Hi Joel, Thank you for your response. Joel Facou wrote: >Aren't Fusion::tuples extendable by using some macros already ? I don't know, could you please point me to an example ? How can I do that ? I searched for a solution and I could not find any so I started to change the header files myself. I am stuck on a compiler error right now but I want to give it another try before posting a question. Anyway, a macro to extend it would be much better. If some one could point me in the right direction it would be great. Thanks again, Mauricio. >> Hi, >> >> Has anybody extended the 10 template parameters in boost::tuples ? >> >> I've written a class named FixedColumnsParser that parses files with >> fixed columns sizes but now I've got a file with more than 10 columns. >> >> In case nobody has done it before I am willing to do it myself and I >> just need to confirm if these are the only files I need to change to >> accomplish that: >> >> tuple_basic.hpp >> tuple_basic_no_partial_spec.hpp >> >> Thank you for your attention ! >> >> >> P.S.: >> Will the coming variadic templates in C++0x solve this in a more >> elegant way ? >> C++ Builder 2009 promisses C++0x support but I have downloaded the >> trial and it is not supporting variadic templates yet. >> -- -- Mauricio Gomes Pensar Digital 55-11-8319-9610 (Brazil - mobile)

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Inline functions in boost/utility
by Timenkov Yuri 12 Feb '09

12 Feb '09

Hi Looking through assembly code of simple test produced by gcc with optimization, I've noticed that free functions in utility/value_init.hpp (get and set) are not declared as inline, though its body consist only of prologue and epilogue. Is there any reason for this or just a bug?

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Inverval timer.
by Alexei Sergeev 12 Feb '09

12 Feb '09

Hello, I want some function / functor to run every n seconds, is there right timer in boost for that? I tried to loop deadline_timer but wasn't able to get it work more than one time. Here is part of code I tryied: //bool _isOnline; // status of internet connection. //boost::asio::io_service _ioService; // need for boost timers. //boost::asio::deadline_timer _internetConnectionTimer; void Logic::InitializeInternetConnectionChecking( long secondsInterval ) { _internetConnectionTimer.expires_from_now( boost::posix_time::seconds( secondsInterval ) ); _internetConnectionTimer.async_wait( boost::bind( &Logic::CheckInternetConnection, this ) ); _ioService.poll(); } void Logic::InitializeInternetConnectionChecking() { InitializeInternetConnectionChecking( 5 ); } void Logic::CheckInternetConnection() { if ( _isOnline = IsLanOrRasInetConnect() ) onOnline(); else onOffline(); _ioService.reset(); InitializeInternetConnectionChecking(); }

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Re: [Boost-users] [multi_index] Problem of scope with the replace in static data structure
by Rodrigo Dias Ferreira 12 Feb '09

12 Feb '09

Hi Joaquim, I saw what you meant, and I have changed... But still if I use the same graph_h, still I got the same problem: Here it is my solution for the Graph constructor: Graph(const Graph &g) : _rangeBegin(g._rangeBegin), _rangeEnd(g._rangeEnd), _nodeRep(g._nodeRep), _nodeNameRep(g._nodeNameRep), _localPropRep(g._localPropRep), _globalPropRep(g._globalPropRep){ //_nodeRep::_uniqueName* Initialization pair<nodeMapIt,nodeMapIt> rangeNodeIt; nodeMapIt tmpNodeIt; rangeNodeIt.first = g._nodeRep.begin(); rangeNodeIt.second = g._nodeRep.end(); while (rangeNodeIt.first != rangeNodeIt.second){ _nodeRep.insert(nodeMap( &*(_nodeNameRep.find(rangeNodeIt.first->_uniqueName->_name)), rangeNodeIt.first->_timestamp, rangeNodeIt.first->_node)); ++rangeNodeIt.first; } } I've debugged, but I didn't see anything suspicious anymore... Did you see something else? thanks, Rodrigo -------- Original-Nachricht -------- > Datum: Wed, 11 Feb 2009 18:26:33 +0100 > Von: joaquin(a)tid.es > An: Rodrigo Dias Ferreira <rodrigodias(a)gmx.de> > Betreff: Re: [multi_index] Problem of scope with the replace in static data structure > Rodrigo Dias Ferreira escribió: > > Hi Joaquim, > > > > > > > >> Can you please test the following? In your //Test of the > >> commit section, rather than reuse graph_h please use a different > >> variable to do the after-commitChanges check: > >> > >> [...] > >> > >> Does this make any difference? > >> > > Yes, it worked, if I instantiate another object (like graph_h2). > > After that I have done some more Debug to try to find the reason, > > but I still don't understand, because inside the constructor it > > finds the Nodes, when I use the same object (graph_h)... > > Inside the overloaded operator-> does not work anymore, even I > > am using the _localGraph in both stretch of codes. > > So if it was the assignment of the _localGraph, it should not > > work with the constructor also, isn't true? > > > > What happens when you do *not* use graph_h2 is that, upon reassigning > graph_h in > > graph_h = Graph_h(it); > > the previous value of graph_h is destroyed, and presumably this leaves > some dangling pointer/iterator when it shouldn't. > > I've examined your code in search for candidates to potential dangling > pointers/iterators and found something a little suspicious: Graph contains > the following two member variables: > > uniqueNameTable _nodeNameRep; > nodeIndex _nodeRep; > > where uniqueNameTable is a container of uniqueNodeNameStruct's and > nodeIndex is a container of nodeMaps pointing to > uniqueNodeNameStruct's in _nodeRep, right? If so, default copy semantics > of Graph is flawed; consider: > > Graph g2; > { > Graph g1; // g1._nodeRep elements point into g1._nodeNameRep > g2=g1; // g2._nodeRep elements point into g1._nodeNameRep > } // g1 is destroyed > // g2._nodeRep elements point to destroyed objects > > See what I mean? Pointers inside _nodeRep are not reassigned on > copy. Does the copy constructor of Graph take this issue into > account? > > If this leads nowhere, you can always try setting up Boost.MultiIndex > safe mode: > > http://boost.org/libs/multi_index/doc/tutorial/debug.html#safe_mode > > and see if some safe mode assertion is triggered. > > Joaquín M López Muñoz > Telefónica, Investigación y Desarrollo -- ************************************************* Rodrigo Dias Ferreira Master Student of Computational Engineering Technische Universität Dresden - Germany E-mail: rodrigodias(a)gmx.de ************************************************* Jetzt 1 Monat kostenlos! GMX FreeDSL - Telefonanschluss + DSL für nur 17,95 Euro/mtl.!* http://dsl.gmx.de/?ac=OM.AD.PD003K11308T4569a

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tuples with more than 10 template parameters.
by Mauricio Gomes 12 Feb '09

12 Feb '09

Hi, Has anybody extended the 10 template parameters in boost::tuples ? I've written a class named FixedColumnsParser that parses files with fixed columns sizes but now I've got a file with more than 10 columns. In case nobody has done it before I am willing to do it myself and I just need to confirm if these are the only files I need to change to accomplish that: tuple_basic.hpp tuple_basic_no_partial_spec.hpp Thank you for your attention ! P.S.: Will the coming variadic templates in C++0x solve this in a more elegant way ? C++ Builder 2009 promisses C++0x support but I have downloaded the trial and it is not supporting variadic templates yet. -- Mauricio Gomes Pensar Digital 55-11-8319-9610 (Brazil - mobile)

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Unit test framework and environment initialization/finalization
by Vinokurov, Aleksandr 12 Feb '09

12 Feb '09

Hello all, My name is Aleksandr Vinokurov, I've just read the site docs on Boost.Tests and now I start writing tests. And realized that there were nothing told about initialization and finalization of the environment of the test suite. I mean some kind of solid calling my finalization function to properly stop the environment, like a try {} final {} in Java -- even if the test fails by BOOST_REQUIRE or BOOST_FAIL. Any suggestions or recommendations from gurus? Oh, just remembered: I use 1.33 version of Boost. With best wishes, Aleksandr Vinokurov Senior Software engineer CJSC "PETER-SERVICE" ========================== Work tel:+7(812)326-12-99 ext. 5039 Fax tel:+7(812)326-12-98 E-mail: mailto:aleksandr.vinokurov@billing.ru URL: http://www.billing.ru

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[xpressive] static expression adding
by Jan Boehme 12 Feb '09

12 Feb '09

Hi, is it possible to add an expression to an already existing expression object? Something like: sregex re = '$' >> +_d >> '.' >> _d >> _d; replace by: sregex re = '$'; re += +_d; re += '.' >> _d >> _d; My attempts did result in compile time troubles. Thanks for helping, Jan.

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