October 2005 - Boost-users - lists.boost.org

[serialization][any]Do we have serialization support for boost::any?
by Li Lirong 11 Oct '05

11 Oct '05

Hi, Do we have serialization support for boost::any? If not, how is it possible to serialize boost::any? Regards, Lirong

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[BGL] Multiple adaptations of graph
by Andreas Brinck 11 Oct '05

11 Oct '05

Hi, I have a simple directed graph class (let's call it MyGraph) which I want to adapt for BGL algorithms. I've defined the necessary traits and functions (in_edges, target etc.) and everything works fine. Problem is I want to be able to treat the graph as an undirected graph as well when using some of the BGL algorithms, but since the graph_traits are only templatized on the graph type I can't define a new set of traits since graph_traits<MyGraph> is already defined. The only solution I've come up with so far (after 10 minutes of thinking :) is to define a new class, MyDirectedGraph, which is an exact copy of MyGraph and define a set of traits for this new class. And then when I want to use the undirected version of the algorithms on my MyGraph object I cast it to a MyDirectedGraph. Somehow I have a feeling there must be a more robust and elegant way to solve this problem. Regards /A.B. ########################################### This message has been scanned by F-Secure Anti-Virus for Microsoft Exchange. For more information, connect to http://www.f-secure.com/

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Bug in boost::regex_match 1.33.0 Win64/cl1400 and Linux/gcc323
by rlop＠gmx.de 11 Oct '05

11 Oct '05

Hello, After upgrading from boost 1.32 to boost 1.33.0, we get an exception in boost::regex_match. The exception is std::runtime_error: Regular expression too big , and only under Win64/cl1400 and RHEL/gcc323 Changing the regex slightly sometimes avoids the exception... Attached a small example, which can be used to reproduce the exception. #include <boost/regex.hpp> int main(void) { boost::regex validValue = boost::regex("([x]{0,64})?"); boost::regex_match("T",validValue); return 0; } best regards Robert Lopuszanski -- 5 GB Mailbox, 50 FreeSMS http://www.gmx.net/de/go/promail +++ GMX - die erste Adresse f�r Mail, Message, More +++

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Arrays in Boost::Python
by Wyatt Greenway 11 Oct '05

11 Oct '05

How do I acomplish this: class A { public: int *Buffer; vector<string> Array; A() { this->Buffer = new int[10]; /* Set items in Buffer */} } /* Boost code */ class_<A>("A") .def("Buffer", &A::Buffer) .def("Array", &A::Array) ; /*-----*/ And in python it would look like so: > MyA = A() > print MyA.Buffer[0] > MyA.Array.append("Hello world!") > print MyA.Array[0] ??????? Thanks in advance for any help

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boost::any Question
by Piyush Kapadia 10 Oct '05

10 Oct '05

I am new user of Boost, I tried to use boost::variant first, but in comparison to boost::any performance of boost::variant appears to be around 4 times slower, so settled for boost::any. Also boost::any has cleaner interface but I don't know how to query current type information for boost::any ? My code looks like following map<unsigned int, boost::any> result_table; result_table[1] = 543.434; vector<int> vec; .. Some vec population code; result_table[2] = vec; Now I need to develop a stringify function for result_table; I can fetch the results back as boost::any value = result_table[2]; But I need to know the type of value, so that I can treat it accordingly to stringify; I know there exists type_traits, but very limited examples of type_traits is provided on Boost documentation and particularly, I am clueless about how to use type_traits in above context to find out what is the current type returned by result_table[int] Also I want to know if Boost has any Hash map implementation that can be superior in performance compare to regular std::map ?? Thanks, Piyush

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[BGL] Simple question about accessing vertex property
by Giulio Veronesi 10 Oct '05

10 Oct '05

Hi, How do I access the vertex_index property of a vertex? Is it necessary to use the get function? More precisaly, let us consider the following: typedef adjacency_list<vecS, vecS, bidirectionalS, no_property, property<edge_weight_t, int> > TGraph; typedef graph_traits<TGraph>::vertex_descriptor TNode; Suppose that 'vertex' is a TNode. Is it correct to do int idx = vertex; to get in idx the vertex_index of vertex? Thanks in adavnce, Giulio

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Boost Serialization Question.
by Piyush Kapadia 10 Oct '05

10 Oct '05

I am able to use Boost XML and TEXT serialization but Binary Serialization fails to read file, though it can write binary file. Is Binary Serialization fully Supported and if so does it work with STD container classes ?

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Re: [Boost-users] __stdcall bind-s with boost::bind andboost::lambda
by Bulygin, Sergey 10 Oct '05

10 Oct '05

boost::lambda::bind<RetType>(..) works like a charm. :) Thanks a lot, Peter! Sergey Peter Dimov wrote: > To bind to __stdcall calling convention function with boost::bind, > there is a macro to define: BOOST_BIND_ENABLE_STDCALL. How can I do > the same (bind to __stdcall-type function) with boost::lambda::bind? You may want to try specifying the return type explicitly as in bind<void>(my_stdcall_function, _1, 0) and see if it helps.

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__stdcall bind-s with boost::bind and boost::lambda
by Bulygin, Sergey 10 Oct '05

10 Oct '05

To bind to __stdcall calling convention function with boost::bind, there is a macro to define: BOOST_BIND_ENABLE_STDCALL. How can I do the same (bind to __stdcall-type function) with boost::lambda::bind? Thank you, Sergey

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Type List Iteration?
by Duane Murphy 10 Oct '05

10 Oct '05

How do I iterate over a type list and call a function? MPL? I have a base class BASE that has several subclasses A, B, C that have special capabilities, but no way to identify those capabilities aside from the type. I would like to determine if an object of type BASE is also of one of the special subclasses: ie void f( BASE* base) { if ( dynamic_cast< A* >( base ) != NULL ) { some_function( dynamic_cast< A* >( base ) ); } else if ( dynamic_cast< B* >( base ) != NULL ) { some_function( dynamic_cast< B* >( base ) ); } else if ( dynamic_cast< C* >( base ) != NULL ) { some_function( dynamic_cast< C* >( base ) ); } } I think you can see why I'd like a type list iterator solution to this. I have arranged for the some_function to be a template as well to make things easier. What I am looking for is the equivalent of find_if() but for types and done at run time. I looked over MPL, but MPL seems to apply at compile time without a door to the run time world. :-) Thanks for your helpful tips! ...Duane

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