- Boost-users - lists.boost.org

[LAMBDA] calling a function pointer stored in a struct
by Imre 07 Apr '06

07 Apr '06

Hi I'm new to the boost::lambda lib, and have a problem. I have a list that stores struct objects. One field of the struct is a function pointer. I'd like to call the function pointer stored in each element of the list, but I can't get it right. First, I tried something like this: struct S { typedef void (*Func)(); Func f; ... }; ... std::list<S> l; ... for_each(l.begin(), l.end(), bind(&S::f, _1)); I think this doesn't work because the bind yields a function object that returns f itself, but doesn't call it. Instead, I'd need to build a function object that returns the result of calling the f stored in the current list node. Unfortunately, I don't know how to do it. Thanks for any help. Imre

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How to parse_config_file with blank key value?
by Matt England 07 Apr '06

07 Apr '06

Summary: Is it possible for the program_options parse-config-file capability to support a config file that has a "blank" keyword value as per this config file example: ---- cut here ---- username= password= ---- cut here ---- This file would be parsed as if there's no value set for these keys/parameters/settings. More background: I manage a development group that uses Boost, and our developers aren't sure how to do this, and I'm posting on their behalf. The answer is not obvious to me at: http://boost.org/doc/html/parse_config_file.html Are there other, pertinent docs? We want to do this to assist the users of our software to know which values *can* be set...without setting them in a default config file. -Matt

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Re: [Boost-users] Serialization: crash at launch ofprogram(duetoboost::serialization::base_object)
by RIVASSEAU Jean Noel 07 Apr '06

07 Apr '06

Ok, I will try to send a small example to the list tomorrow. In fact I think everything lies in the fact that using boost::serialization::base_object also registers the fact that the classes are parent and child. The serialization system needs to know that in order to make casts later. Somehow it probably does not like it when it tries to register several different classes as the parent of the same class. Jean-Noël -----Message d'origine----- De : boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] De la part de Robert Ramey Envoyé : jeudi 6 avril 2006 17:20 À : boost-users(a)lists.boost.org Objet : Re: [Boost-users] Serialization: crash at launch ofprogram(duetoboost::serialization::base_object) I would be wiling to look at a small example which demonstrates the problem. Robert Ramey RIVASSEAU Jean Noel wrote: > I have tried to use versioning. Exact same problem. > > More explanations: if I use the version facility, and at load I > switch the boost::serialization::base_object<MyBaseClass> depending > on the version, the same crash will happen. > > Eg: this code: > > if (version == 0) > { > boost::serialization::base_object<MyBaseClass_1> > } > Else > { > boost::serialization::base_object<MyBaseClass_2> > } > > Will cause the same crash. > > So, could you look at the code, because currently there is no way to > change the base class of an object appearing in serialized archives, > if you want to be able to read old archives. > > It seems like there is a bug, if the base_object is used several > times with different classes, the crash will appear. > > Thanks > > Jean-Noël > > > -----Message d'origine----- > De : boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] De la part de Robert > Ramey > Envoyé : mercredi 5 avril 2006 17:15 > À : boost-users(a)lists.boost.org > Objet : Re: [Boost-users] Serialization: crash at launch of program > (duetoboost::serialization::base_object) > > The "version" facility is provided for maintaining the ability to > read old > archives. It doesn't sound like you're using this and its sounds > like you > should be. > > Robert Ramey > > > "RIVASSEAU Jean Noel" <JN.RIVASSEAU(a)oberthurcs.com> wrote in message > news:87F60F7FA02FF749AFB02BD9FCAA6B0401074928@naserv31.nanterre.oberthurcs.com... > Hello, > > My program crashes at launch (not even a exit(0) as the first line of > main(int argc, char *argv[]) will stop it from crashing), due to the > BSL. > > What I am trying to do is: I have a class, whose serialization is > split (eg, > save and load functions are provided, and they are different). Now > this > class had a parent class, so I used to call > boost::serialization::base_object<MObject>() on the base class > MObject. > > However I want to change the parent of my class to a different class. > I also > want to update my old archives, so I decided to leave the load > function of > my class untouched, while I would change the save function, to update > the > call to base_object to the new parent class (not MObject anymore). I > thought > it would work, since it would load the old archive using the same > method, > but save it using the new, so I would have ran only one time the > program and > the archive would be updated (then, of course, before running it > again I > would have to recompile it one more time with the correct changes to > the > load function). > > But it does not work as expected, since it seems the BSL does not > like the > fact that save and load functions calls to > boost::serialization::base_object > do not specify the same base class. It does not complain at compile > time but > crashes at run time before even entering main and certainly before > loading > any archive. The crash is due to a NULL pointer, I have tried to > debug with > gdb but the crash apparently occurs on the _libkernel32_a_iname () so > I do > not not know where it is (too low level for me). > > Robert, do you have an idea what is going on? I suspect a bug - > however if > it is "normal" behaviour (I think it should then throw an exception > rather > than crash), > > *** > Tell that to the author of _libkernel32_a_iname () > > do you have an idea how could I update my archives? I need to change > the > parent of this class, but need to be able to read my old archives - > and > changing them "by hand" by looking into the XML archive code is tool > hard. > > Thank you, regards > > Jean-Noël Rivasseau > > > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users =

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iterator_adapter conversion to base iterator?
by Sebastian Weber 07 Apr '06

07 Apr '06

Hello everybody! Please don't blame for beeing foolish - I'm using the iterator-adapter class for the first time. I converted a standard iterator from a std::vector with the iterator_adapter stuff into another class random_set_iterator. But at certain points in my programm I need the random_set_iterator converted back to the original iterator class from the vector class. I noticed the base()-function which basically does the job, but I think there should be a more elegant and clearer way to do it. Am I wrong or shouldn't an adapted iterator almost always be convertible to it's base iterator? I'm sure, it should not hard to implement somthing like this, but how? Thanks in advance! Greetings, Sebastian

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I NEED HEMP PLEASEeeeeeeeeeeeeee
by Karim Bakir 06 Apr '06

06 Apr '06

I use multi array boost But I have problem : - I can't declare a multi array as a member variable , I have the error: unexpected "error C2321: syntax error : unexpected 'boost::extents" When I don' write the keyword "typdef" I have more mistakes. //Boost library #include <Boost/multi_array.hpp> #include <cassert> //Name Space using namespace std; using namespace boost; class MyClass { typedef boost::multi_array<double,2>array_type_2d; public: MyClass(); virtual ~MyClass(); array_type_2d M(boost::extents[10][10]); }; So I want to have : but I don't manage it. //myClass.h ////////////////////////// //Boost library #include <Boost/multi_array.hpp> #include <cassert> //Name Space using namespace std; using namespace boost; class myClass { boost::multi_array<double,2>array_type_2d; private : int dim1, dim2; array_type_2d MyMatrice(boost::extents[dim1][dim2]) ; array_type_2d MySecondMatrice(boost::extents[10][10]) ; }; //myClass.cpp //////////////////////////////// void myClass::tester() { for (int i= 0 ; i<dim1; +) for(int j=0;j<dim2;j++) MyMatrice[i][j] = 15; } for ( i= 0 ; i<10; +) for(int j=0;j<10;j++) MySecondMatrice[i][j] = 0; } Thankssss

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Please add support for Borland C++ Builder 2006
by Zhou Fan 06 Apr '06

06 Apr '06

Please add support for Borland C++ Builder 2006. I need it very much.

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signal type declaration problem
by Emre Birol 06 Apr '06

06 Apr '06

Hi all, I have a class like below and I want to declare a signal type inside my class. Unfortunately when I do that MS VC80 complaints. Any help highly will be appreciated. template <typename T> class MyTask { public: // type definitions typedef enum { waiting, running, completed, failed } States; typedef boost::signal<void (States)> StatusChanged; typedef boost::signals::connection Connection; }; I get two warnings first then an error: Warning 1 warning C4512: 'boost::signals::detail::bound_objects_visitor' : assignment operator could not be generated c:\lib\boost\include\boost-1_33\boost\signals\trackable.hpp 185 Warning 2 warning C4346: 'boost::signal<void(lumentest::NITask<trait>::States)>::slot_function_type' : dependent name is not a type c:\projects\tesla-at-sti\src\lumentest\devices\nitask.hpp 124 Error 3 error C2061: syntax error : identifier 'slot_function_type' c:\projects\tesla-at-sti\src\lumentest\devices\nitask.hpp 124 if I replace 'States' with an int type then it works. I think compiler can't find out the type of States properly... I've also tried following declarations. None of them worked. typedef boost::signal<void (MyTask::States)> StatusChanged; typedef boost::signal<void (MyTask<T>::States)> StatusChanged; typedef boost::signal<void (typename MyTask::States)> StatusChanged; thanks, Emre

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[review] promotion traits - review period extended until April 9.
by Tobias Schwinger 06 Apr '06

06 Apr '06

Dear users & members of Boost, I decided to extend the review period of the fast-track review for Promotion Traits until April 9 because there were only three reviews until now. That is, you have another three days to submit your evaluation of the proposed Boost software. Cheer up, it's a small & fast-to-track submission! We're very much looking forward to your reviews. Download URL ============ http://cpp-experiment.sourceforge.net/promote-20050917.tar.gz About the submission ==================== The Promotion Traits extend Boost.TypeTraits with templates that compute the type after promotion has been applied. Example: // given template<typename T> struct some_algorithm; template<> struct some_algorithm<int> { [...] }; // [...] more specializations // , [...] some_algorithm< typename integral_promotion<T>::type > [...] // makes some_algorithm work for any type T that promotes to an integer // (that is enums and smaller integral types) without the need for // additional specialization Review questions ================ Please always explicitly state in your review, whether you think the library should be accepted into Boost. You might want to comment on the following questions: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? Regards, Tobias (Review Manager)

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(no subject)
by Karim Bakir 06 Apr '06

06 Apr '06

Hi I want to know if it exists in boost multi array a method to empty it. thanks. --------------------------------- Nouveau : téléphonez moins cher avec Yahoo! Messenger ! Découvez les tarifs exceptionnels pour appeler la France et l'international.Téléchargez la version beta.

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sregex_token_iterator
by Jean-Sebastien Vachon 06 Apr '06

06 Apr '06

Hi All, I have a string in the following form: w="id = 10" C=field1 G=GeoRaster X=leMHG08wViX2quWNB All I want is to iterator onto the key/values pairs. w "id = 10" C field1 G GeoRaster X leMHG08wViX2quWNB The key/value pairs are separated by spaces. However, I can not simply use a space pattern to iterate over my input string since the W option allows the user to use "" to include spaces. Can someone tell me what is wrong in the following code? oParametersValue represents my input string. regex eParam("(.)=(\"?.*\"?)", regex::normal | regbase::icase); int const sub_matches[] = { 1, 2 }; // key, value sregex_token_iterator oIter(oParametersValue.begin(), oParametersValue.end(), eParam, sub_matches); sregex_token_iterator j; while (oIter != j) { std::cout << *oIter++ << std::endl; } Thanks

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