March 2005 - Boost-users - lists.preview.boost.org

Boost.Jam
by Eyal Inbar 29 Mar '05

29 Mar '05

When I run bjam i get /lib/i686/libc.so.6: version 'GLIBS_2.3' not found (required by bjam) What i need to do? eyal

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RE: [Boost-users] compile error
by Eyal Inbar 29 Mar '05

29 Mar '05

Thank It's in CPPFLAGS. but i found it after i look into the Makefile and try some arguments. Now i found that in /root/.bash_profile i set CXX to be my compiler command export CXX="g++ -ftemplate-depth-31" and it works with all the projects Eyal -----Original Message----- From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org]On Behalf Of Malte Starostik Sent: Monday, March 28, 2005 4:30 PM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] compile error Eyal Inbar schrieb: [how to add -ftemplate-depth-NN] > Thanks > But how and where can i changed the flag in g++ ? I don't know exactly where it is in KDevelop, but usually in IDEs, somewhere in the project options you can add/change compilation flags. Look around in the options, check the manual. For often used flags there may be predefined options to check, for things like the template depth you probably have to enter -ftemplate-depth-NN where NN is the desired value manually in some "extended options" or similar field. HTH, Malte _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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delete shared_ptr object???
by Dan Bikel 29 Mar '05

29 Mar '05

Rather disturbingly, the following code compiles (at least, with g++-3.3.2): #include "boost/shared_ptr.hpp" using namespace boost; class X {}; int main() { const shared_ptr<X> y; delete y; } Normally, when you compile code with delete applied to a non-pointer type, you get a compile-time error. What's going on here? TIA, Dan.

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regex expressions in boost::regex vs python, how to get the answer from boost
by Alexis H. Rivera-Rios 29 Mar '05

29 Mar '05

Hi, I'm playing around with the boost::regex library and I want to match two tokens from a filename. For example files with the following format: myname_123.dat I want to be able to determine the string and number separated by the underscore. So the result of my match should be "myname", and 123. In python, I can do it like this: import re >>> x = 'myclass_123.dat' >>> result = re.match(r'(\w+)_(\d+)\.dat$', x) >>> result.group(1) 'myclass' >>> result.group(2) '123' I'm having problems getting the same result in C++. This is the sample program: int main(int argc, const char** argv) { boost::regex expression("(\\w+)_(\\d+)\\.dat$"); std::string filename(argv[1]); boost::cmatch what; if(boost::regex_search(filename.c_str(), what, expression)) { for (int i=0;i<what.size();++i) { std::cout << what[i].first << " " << what[i].second << std::endl; } } return 0; } The output of this program is: > openmp3 alexis_1023.dat alexis_1023.dat alexis_1023.dat _1023.dat 1023.dat .dat How do I get my groups "alexis", 123 as in Python? Thanks, Alexis Programming Tutorial: In Python: To do this, do this In Perl: To do this, do this or this or this or this... In C: To do this, do this, but be careful In C++: To do this, do this, but don't do this, be careful of this, watch out for this, and whatever you do, don't do this __________________________________ Do you Yahoo!? Yahoo! Small Business - Try our new resources site! http://smallbusiness.yahoo.com/resources/

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Any interest in postconstruction/predestruction facility?
by Malte Starostik 29 Mar '05

29 Mar '05

Hi, I'm using a wrapper class to automate postconstruction and predestruction. A preliminarily boostified version (added licence header, changed namespace to boost) is available at http://malte.homeip.net/~malte/prepost/ prepost.hpp[.html] contains the library The file example.cpp[.html] shows an example usage: The class thread_base starts a new thread in it's post_construction() member function which runs the virtual run() member function in the new thread. Since run() is to be overridden by a derived class, this cannot be done by the ctor. Similarly, the thread is joined in the pre_destruction() member function, as the dtor would be too late since the derived class's instance must not have been destructed before the thread finished. The basic usage is to derive a class X from post_constructed and/or pre_destructed according to which facilities are needed. Then, instead of instantiating X directly, user code instantiates prepost_wrapper< X >. Direct instantiation of X is prevented by the presence of pure virtuals in the classes post_constructed and pre_destructed. As in most if not all cases, X will be polymorphic anyway, I considered the benefit of prevented circumvention of the mechanism worth the two additional entries in the vtable. Is there any interest in having this facility? BTW, the name prepost_wrapper is definately the result of my lacking imagination. Any suggestions appreciated ;-) Outstanding issues: * maybe prepost_wrapper should prevent being used as an intermediate class * the forwarding ctors of prepost_wrapper are problematic if one or more of the base class's ctors are explicit * the hardcoded maximum number of ctor args should be configurable * anything else I didn't think of? BTW, I tried to have the default ctor generated by the BOOST_PP_REPEAT macro as well, but failed miserably to find a way to omit template<> if n is 0. Some help in this area is appreciated as well. Cheers, Malte

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BGL: subgraph and bundled properties
by Wintermantel, Marc 28 Mar '05

28 Mar '05

Hello, I would like to create a graph-tree structure (subgraph concept) with bundled properties. The creation of the graphs works fine. However the interface for bundled graphs seems not to be implanted in subgraph. Is this right? Is it just forgotten in subgraphs or does the concept of bundled properties and subgraph not work together. Cheers, Marc

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[C++ Template Metaprogramming] Selected Answers Posted
by David Abrahams 28 Mar '05

28 Mar '05

Ariel Badichi has generously established a wiki page containing his answers to many of the exercises in the book "C++ Template Metaprogramming: Concepts, Tools, and Techniques from Boost and Beyond" by me and Aleksey Gurtovoy. Please see the book's home page at http://www.boost-consulting.com/metaprogramming-book.html for details. -- Dave Abrahams Boost Consulting www.boost-consulting.com

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RE: [Boost-users] compile error
by Eyal Inbar 28 Mar '05

28 Mar '05

Thanks But how and where can i changed the flag in g++ ? eyal -----Original Message----- From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org]On Behalf Of Malte Starostik Sent: Monday, March 28, 2005 5:37 AM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] compile error Eyal Inbar schrieb: > Hello > > I download boost to window2000 OS and run the quick_tour.cpp on VC++ 6 > without trouble. > > But when i run it on linux with KDevelop i get > > /usr/local/include/boost/iterator/iterator_adaptor.hpp:218: template > instantiation exceeds > > maximum of 17 (use -ftemplate-depth-NN to increase the maximum) ^^^^^^^^^^^^^^^^^^^ here... > instantiating 'struct > > boost::mpl::eval_if<boos::is_convertible<random_access_itarator_tag, > > boost::incrementable_traversal_tag>,boost::mpl::identity<random_access_iterator_tag>, > > boost::detail::old_category_to_traversal<random_access_iterator_tag> >' ...it tells you what to do. The C++ standard speficies a limit of 17 for recursively nested template instantiations. To have g++ accept deeper nested templates, add sth. like -ftemplate-depth-20 (or more than 20 as needed) to the compile command (CXXFLAGS). Now I wonder whether "recursively nested" applies only to a< a< a< a< ... > > > > or also to a< b< c< d< ... > > > > and g++ misinterpreted that... HTH, Malte _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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[mpl] instantiating long_<MAX_LONG> generates warning on VC7.1/.NET
by Yariv Tal 28 Mar '05

28 Mar '05

On Visual Studio.NET / VC7.1 the following code: #include <boost/mpl/long.hpp> #include <climits> boost::mpl::long_<LONG_MAX> lll; Gives the following warning: ...\boost_1_32_0\boost\mpl\aux_\integral_wrapper.hpp(72) : warning C4307: '+' : integral constant overflow ...\main.cpp(39) : see reference to class template instantiation 'boost::mpl::long_<N>' being compiled with [ N=2147483647 ] Obviously, the compiler is right about the overflow, and, IMHO, the same holds for using any maximal/minimal value for a specific type. Is this a known issue? Does it cause any actual problems? (in other words: can I ignore the warning? always? sometimes? never?) Thanks, Yariv Tal.

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Boost.program_options config files
by Sean DeNigris 28 Mar '05

28 Mar '05

Is there an easy way to work with Boost.program_options config files? I want to be able to write option values to the file programmatically.

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