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

Container/Algorithm question
by Elisha Berns 15 Jul '05

15 Jul '05

Hi, I have some confusion regarding which type of container/algorithm to use to optimize the lookup (not necessarily the insertion) of unique pairs where the definition of unique is: Either member of the pair can occur an infinite/unbounded number of times provided the other member of the pair never occurs more than once: (3,4), (3,5), (3,6), (6,6), (5,6), (4,6)... etc. So what am I looking at? Some container that allows multiple keys of the same value provided the value is always unique. And also multiple values of the same value provided the key is always unique. Is there such a thing, or something better suited? Thanks, Elisha Berns e.berns(a)computer.org tel. (310) 556 - 8332 fax (310) 556 - 2839

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tuple
by Jim Pritts 15 Jul '05

15 Jul '05

Hello, Is it possible to do something like the following: typedef boost::tuple<double, int, int> element; std::vector<element> d; std::vector<element>::iterator i = std::max_element(d.begin(), d.end(), bind(std::max<double>,bind(get<0>,_2),_1)); In other words, I would like the functionality of select1st with std::pair. Thanks, Jimmy.

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partial specialization: mpl?
by Cory Nelson 15 Jul '05

15 Jul '05

I have a function like: template<typename CharT> void foo() { std::basic_string<CharT> str; ... if(str=="bar") ... } I'd like to check at compile time if CharT is a char or wchar_t to specialize the string used to compare- MPL seems like the thing I would use for this but documentation on doing this seems scarce. Could someone give me an example? -- Cory Nelson http://www.int64.org

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Re: [Boost-users] How to serialize a derived class object withbaseclass pointer?
by Yan Zhang 14 Jul '05

14 Jul '05

Hi Robert, I know that it works for abstract base class. But if the base class is not abstract class how you do it? Is it possible? Thanks, yan _____ From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Robert Ramey Sent: Monday, July 11, 2005 3:55 PM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] How to serialize a derived class object withbaseclass pointer? try making the base class a polymorphic class by adding the following changes: virtual ~CMyCls1() = 0; "Yan Zhang" <Yan.Zhang(a)mitchell.com> wrote in message news:F96935FCB9C3D549B3B6CD8915811A2F0FF00C7C@mail60nt.mitchell.com... Hi, I'm trying to serialize an object of derived class with a base class pointer, somehow only base class's serialization member function got called. Here is the code (simplified): class CMyCls1 { public: CMyCls1() : m(10) {} ~CMyCls1() {} private: friend class boost::serialization::access; template<class Archive> void serialize(Archive &ar, const unsigned int version) { ar & BOOST_SERIALIZATION_NVP(m); } int m; virtual ~CMyCls1() = 0; }; class CMyCls2 : public CMyCls1 { public: CMyCls2() : x(1.5) {} ~CMyCls2() {} private: friend class boost::serialization::access; template<class Archive> void serialize(Archive &ar, const unsigned int version) { ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(CMyCls1); ar & BOOST_SERIALIZATION_NVP(x); } double x; virtual ~CMyCls2(); }; void main () { CMyCls1 *pmycls = new CMyCls2; ... oa.register_type(static_cast<CMyCls1 *>(NULL)); oa.register_type(static_cast<CMyCls2 *>(NULL)); oa << BOOST_SERIALIZATION_NVP(pmycls); ... } Look at the archive file, only base class data is serialized. Actuall, CMyCls2::serialization() is not called at all. How do you serialize a derived class object with a pointer of base class? Thanks, Yan _____ _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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Re: [Boost-users] Compile errors using make_zip_iterator
by Dalton, Barnaby 14 Jul '05

14 Jul '05

I tried the same code with the CVS version and it compiled fine. Thanks Barney -----Original Message----- From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of David Abrahams Sent: Friday 08 July 2005 16:23 To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] Compile errors using make_zip_iterator "Dalton, Barnaby" <Barnaby.Dalton(a)brevanhoward.com> writes: > I'm using MSVC 7.1 and am getting masses of compile errors with the > following code (see end of message for the errors): > > #include <boost/iterator/zip_iterator.hpp> > #include <vector> > #include <functional> > #include <boost/detail/workaround.hpp> > > int main( void ) > { > > std::vector<double> vect1(3); > std::vector<double> vect2(3); > > // boost::zip_iterator< > // boost::tuples::tuple< > // std::vector<double>::const_iterator, > // std::vector<double>::const_iterator > // > > // > > // zip_it_begin( > // boost::make_tuple( > // vect1.begin(), > // vect2.begin() > // ) > // ); > > std::vector<boost::tuples::tuple<double, double> > > vect_of_tuples(3); > > std::copy( > boost::make_zip_iterator( > boost::make_tuple( > vect1.begin(), > vect2.begin() > ) > ), > boost::make_zip_iterator( > boost::make_tuple( > vect1.end(), > vect2.end() > ) > ), > vect_of_tuples.begin() > ); > > return 0; > } > > If I uncomment the earlier instantiation of zip_it_begin then it > compiles without any errors! I'm guessing this is some kind of compiler > bug but and am wondering what the correct/most elegant workaround > is? Well, I don't know, but if you haven't already done so you might try the latest Boost CVS instead of 1.32. If the problem disappears that would be the easiest solution. > Do I have make sure I manually declare a zip_iterator somewhere > before using make_zip_iterator? Can't tell ya. I do note that the one you declared is using constant iterators while the one you're building with make_zip_iterator is using mutable iterators. Sorry I'm not more clue-ful here. This looks like a good question for Microsoft support ;-) -- Dave Abrahams Boost Consulting www.boost-consulting.com _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users The information transmitted is intended only for the person(s) or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and delete the material from any computer. This communication is for informational purposes only. It is not intended as an offer or solicitation for the purchase or sale of any financial instrument or as an official confirmation of any transaction. All market prices, data and other information are not warranted as to completeness or accuracy and are subject to change without notice. Any comments or statements made herein do not necessarily reflect those of Brevan Howard Asset Management LLP, its members and affiliates. Brevan Howard Asset Management LLP is authorised and regulated by the Financial Services Authority. Registered Office: 42 Portman Road, Reading, Berkshire RG3O 1EA. Phone number 020 7022 6100.

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Stemming Tools Needed
by Hossein Haeri 13 Jul '05

13 Jul '05

Dear all, Does anybody know any good C++ tool for stemming words? Is there any body on this list who's say writen that using Spirit? TIA, --Hossein ___________________________________________________________ Yahoo! Messenger - NEW crystal clear PC to PC calling worldwide with voicemail http://uk.messenger.yahoo.com

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Serialization -- Which constructor is called?
by Eric 13 Jul '05

13 Jul '05

In debugging a problem, I put breakpoints on the default and copy constructor along with the operator=. When de-serializing the class, none of the breakpoints were hit. I've searched through the documentation and old posts and can't seem to find any reference to which constructor is called from the serialization class. Could someone enlighten me on this? I'm sure it's covered somewhere, but I've somehow missed it. Thanks, Eric Boost 1.32 under Linux

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RegEx Bug
by Robert 13 Jul '05

13 Jul '05

Hello, I have this regex: ^.*(?=(?:.*[A-Z]){2,})(?=(?:.*\d){2,}).*$ According to RegExBuddy, this should match with a string that has two upper cases and two digits. However, using the boost_regex_vc7 dll the result works with two upper case, a single digit, and any other character. For example, AA1! Matches, but it shouldn't. Can someone help me identify if it is RegEx that has the bug, RegExBuddy, or if I am just off my rocker! Thanks Robert

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Re: [Boost-users] Serialization -- Which constructor is called?
by Eric-public 13 Jul '05

13 Jul '05

Sorry, I should have described my usage a bit better. I am de-serializing from a pointer to a class which then contains vectors of other shared_ptr's to yet more classes. None of the default constructors seem to be hitting my breakpoints -- which could be a GDB issue for all I know. I'll add the load_construct_data function to my class to see if that helps. On a side issue, I sometimes get stream_exception's thrown when de-serializing. Since the stream is still good, I'm assuming that this is caused by an un-registered class being de-serialized. Do you have any pointers as to how I can debug this? Thanks, Eric > > >Robert Ramey wrote: > >A couple of hints: > >a) constructor is called only when de-serializing a pointer. So unless >you're doing this you won't see and constructor call. > >b) When creating a new object in the course of de-serializing a pointer, the >function load_construct_data is callled. This calls an in place new for the >default constructor. By specializing this function for your particular >class, you can arrange to call a non-default constructor. > >Robert Ramey > >Eric wrote: >> In debugging a problem, I put breakpoints on the default and copy >> constructor along with the operator=. When de-serializing the class, >> none of the breakpoints were hit. >> >> I've searched through the documentation and old posts and can't seem >> to find any reference to which constructor is called from the >> serialization class. Could someone enlighten me on this? I'm sure >> it's covered somewhere, but I've somehow missed it. >> >> Thanks, >> >> Eric >> >> Boost 1.32 under Linux ________________________________________________ Message sent using UebiMiau 2.7.2

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How to delete all vertices and edges in BGL
by Abhijit Deshmukh 12 Jul '05

12 Jul '05

Hi, I have a mutable property undirected graph. I want to delete all the vertices and edges in the graph. I tried using the for loop for( b = *vertices( databaseGraph ).first; b!= *vertices( databaseGraph ).second; b++ ){ clear_vertex( b, databaseGraph ); remove_vertex( b, databaseGraph ); } This works fine for some extent, but then crashes. My guess is that the loop crashes when it reaches a vertex whose edges have not been deleted. But my speculation was that clear_vertex deletes all the edges associated with a vertex and the function should not crash when clear_vertex is called before remove_vertex. Clearly, I am making a mistake, but am not able to point it out. Can you let me know what is the correct way of deleting all edges and vertices in a mutable property undirected graph. Thanks in anticipation. Regards, Abhijit

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