November 2002 - Boost-users

[Regex] Maybe bug?
by Yaroslav Govorunov 20 Nov '02

20 Nov '02

Hello, All! For example consider expression: (www\.)?(.+?)\.com When using match algorithm and try to match "www.somesite.com" $1 gets "www.somesite" but I thought it should be "somesite". Why (www\.)? is ignored even when non greedy repeats are used? With best regards, Yaroslav Govorunov, E-mail: slov(a)rsdn.ru http://www.rsdn.ru http://www.isapirewrite.com

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regex+old_include on gcc 3.2
by dreamlax 20 Nov '02

20 Nov '02

Hi all, I am using regex library compiled using gcc 3.2 and with the old_include header files. I wrote this code a year ago. While compiling it gives following error.. /boost/old_include/regex.h:410: `jm_def_alloc' not declared /boost/old_include/regex.h:412: `re_alloc_binder' not declared /boost/old_include/regex.h:443: `jm_def_alloc' not declared any ideas.. thanks sandeep

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FW: Object Lifetime Management with Boost-Python V2
by Daniel Paull 19 Nov '02

19 Nov '02

Hi all, I'm having trouble with some object lifetime issues using Boost Python V2. Basically, I'm in a situation where both C++ and Python want to delete the same object. Below is a simple example of the scenario. Consider the two classes A and B. An instance of A is passed to B via the setA() method. B then assumes ownership of A and deletes it in it's destructor. NOTE: the behaviour of the C++ code can not be changed currently. ------------------------------------- class A { public: A() {} ~A() {} }; class B { public: B() : m_a( 0 ) {} ~B(){ if ( m_a ) delete m_a; } void setA( A* a ){ m_a = a; } private: A* m_a; }; --------------------------------------- I have defined a python module thus, being sure to indicate the pointer adoption by using the with_custodian_and_ward<> policy: --------------------------------------- BOOST_PYTHON_MODULE( my_module ) { class_< A >( "A" ) ; class_< B >( "B" ) .def( "setA", &B::setA, with_custodian_and_ward<1, 2>() ) ; } --------------------------------------- All is fine, and I can show that instances of B keep their instance of A alive. However, executing the python code: -------------- a = A() b = B() b.setA() -------------- results in "a" (or rather, the wrapped C++ object) being deleted twice. I can get around this problem by using a free function "createA()" which returns a new instance of "A" using the "return_existing_object" return value policy, but this seems dangerous and can introduce a memory leak if the user does this from python: -------------- def makeLeak(): a = createA() makeLeak() -------------- Perhaps a new call policy is the solution, but I'm not sure how to proceed. Has anyone solved this problem already? Thanks in advance, Daniel Paull Development Lead Fractal Technologies 57 Havelock Street West Perth WA Australia 6005 PO Box 1675 West Perth WA Australia 6872 Phone: +61 8 9211 6064 Mobile: 0408 921 897 Email: Daniel.Paull(a)fractaltechnologies.com

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Extended use of BGL File Dependency Example
by Tom Matelich 19 Nov '02

19 Nov '02

I was excited to get to use the graph library for a dependency tracking tool we needed, now I have a feature that I don't know how to do. This is mapping library/executable dependencies and we have a lot of apps with common sub-libraries. I'd like to extract a full-rebuild order for only certain nodes, i.e. what libs do I need to build for apps A and B? Since its a DAG, I thought something about reachability, perhaps? I'm not to familiar with graph theory :( thanks, Tom ----------------------------------------------------------------------- DISCLAIMER: Information contained in this message and/or attachment(s) may contain confidential information of Zetec, Inc. If you have received this transmission in error, please notify the sender by return email. -----------------------------------------------------------------------

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condition notify_all problem
by joshuaboelter 19 Nov '02

19 Nov '02

I've just started using the boost libraries, threads so far -- great libraries. I have a test app that uses thread groups of producers and consumers working with a queue. It seems simple enough, but I'm encountering a deadlock problem using notify_all() vs looping with notify_one() when ending the consumer threads. I'm not sure my implementation is correct though (link to source below). I can reliably cause deadlocks on all Windows XP systems I've tried (single, dual and quad machines) within about a minute of execution. However, I only had one deadlock on Windows 2000 (single or quad) in over 6 hours of execution and still going. Attaching or running the executable in the VS7 debugger shows all the threads and the main thread stopped in ntdll.dll via kernel32.dll. The stack shows the last user code executed by wmain was boost::thread_group::join_all from ctg.join_all(). The threads last ran boost::condition::do_wait before entering the kernel. Swapping lines 217-218 for 222-227 appears to fix the deadlock by looping with notify_one(). I would guess that something fundamental is wrong with my implementation, and my fix just changes the timing. Any help is appreciated. The source is posted at the link below. I can provide further information if necessary. Thanks, Joshua Boelter www.boelter.org/data/t_threadgroup.cpp Using Visual Studio 7.0.9466, stlport 4.5.3 (dll), boost libraries 1.29.0 on various WinXP Pro and Win2k systems.

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RE: [Boost-Users] Possible boost addition: sub string and const s tring.
by Jim.Hyslop 19 Nov '02

19 Nov '02

Forwarded to main Boost list - that's the more appropriate venue for discussions of possible additions. -- Jim Hyslop boost-users moderator. > -----Original Message----- > From: alexei_novakov [mailto:alexei_novakov@yahoo.com] > Sent: Monday, November 18, 2002 7:05 PM > To: Boost-Users(a)yahoogroups.com > Subject: [Boost-Users] Possible boost addition: sub string and const > string. > > > Hello everyone. > > I have two classes which I found pretty handy: sub_string (behaves as > a mirror of the portion of master basic_string) and const_string (C- > string wrapper). Nice thing about these two is they implemented as > template specialization of basic_string which has advantages: > a) familiar interface; > b) possibility to reuse the code written for basic_string (like > string streams, lexical casts, etc). > > Any interest? > > Regards. > > Alexei Novakov > > > Info: <http://www.boost.org> > Wiki: <http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl> > Unsubscribe: <mailto:boost-users-unsubscribe@yahoogroups.com> > > > Your use of Yahoo! Groups is subject to > http://docs.yahoo.com/info/terms/ > >

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which compiler are you using while using bgl?
by Jun Zhang 19 Nov '02

19 Nov '02

I am a newbie from China, I am sorry about my poor English. I encountered a problem while using bgl. I need your help. and I'd like to know what compiler you are using while using bgl. My Environment: Windows2000 + devc++4.9.6.0(it uses g++ as it's compiler) But it can't compile and run the following example: _________Example start____________ #include <deque> // to store the vertex ordering #include <vector> #include <list> #include <iostream> #include <boost/graph/vector_as_graph.hpp> #include <boost/graph/topological_sort.hpp> int main() { using namespace boost; //create each labels of the tasks const char* tasks[] = { "pick up kids from school", "buy groceries (and snacks)", "get cash at ATM", "drop off kids at soccer practice", "cook dinner", "pick up kids from soccer", "eat dinner"}; const int n_tasks = sizeof(tasks)/sizeof(char*); //create the graph std::vector<std::list<int> >g(n_tasks); g[0].push_back(3); g[1].push_back(3); g[1].push_back(4); g[2].push_back(1); g[3].push_back(5); g[4].push_back(6); g[5].push_back(6); // perform the toplogical sort and output the result std::deque<int> topo_order; topological_sort(g, std::front_inserter(topo_order),vertex_index_map(identity_property_map())); int n = 1; for (std::deque<int>::iterator i = topo_order.begin();i != topo_order.end(); ++i, ++n) std::cout << tasks[*i] << std::endl; system("PAUSE"); } _________Example End_____________ it says: 36 ...\main.cpp instantiated from here I wondered it can compile another example:file_dependencies.cpp, which has also used topological_sort.

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Boost::Threads building ".a" file for MinGW
by ian_ganigan 19 Nov '02

19 Nov '02

Need help ASAP.. I'm new at this. Anyone?

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Possible boost addition: sub string and const string.
by alexei_novakov 19 Nov '02

19 Nov '02

Hello everyone. I have two classes which I found pretty handy: sub_string (behaves as a mirror of the portion of master basic_string) and const_string (C- string wrapper). Nice thing about these two is they implemented as template specialization of basic_string which has advantages: a) familiar interface; b) possibility to reuse the code written for basic_string (like string streams, lexical casts, etc). Any interest? Regards. Alexei Novakov

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Forte 7 Compiler
by ewanbrock 18 Nov '02

18 Nov '02

Hi, I'm trying to compile Boost using the Solaris Forte 7 Compiler. Initial attempts are leading to all sorts of assertion errors. Has anyone had success using boost with this compiler? Does anyone know what the Config options should be ? Many thanks, Ewan

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