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[BGL] Two Grpah Matching Algorithms
by Hossein Haeri 28 Jun '06

28 Jun '06

Dear all, (I don't know whether I'm supposed to post BGL stuff to a more specialised list. Am I?) I was wondering if anybody here has implemented the maximum weight graph matching algorithm for bipartite graphs. Is that already a part of BGL? And, what about the stable marriage algorithm? To stop people from lynching me, this is NOT an assignement; We [1] are running out of time for a paper submission, and, we still need a few more evaluations. That's why I'm in a hurry... So, what I need for the moment is an implementation of the above two algorithms. Any help in this respct would be highly appriciated. TIA, --Hossein [1] Semantic Web Research Laboratory, Computer Engineering Department, Sharif University of Technology (SUT), Tehran, IRAN. http://sw.ce.sharif.edu ___________________________________________________________ Try the all-new Yahoo! Mail. "The New Version is radically easier to use" The Wall Street Journal http://uk.docs.yahoo.com/nowyoucan.html

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[preprocessor] CAT and '-' token
by Johan Nilsson 28 Jun '06

28 Jun '06

Hi, I guess this is more of a regular preprocessor question than a Boost.Preprocessor specific one, but: Shouldn't it be possible to concat tokens starting with (or solely consisting of) a '-'? The example at the end of this posting yields the errors: error: pasting "-" and "debug" does not give a valid preprocessing token error: pasting "foo" and "-" does not give a valid preprocessing token --- #include <boost/preprocessor/cat.hpp> #include <boost/preprocessor/stringize.hpp> #include <iostream> #define MODULE foo #define VARIANT debug #define NAME BOOST_PP_CAT(MODULE, BOOST_PP_CAT(-, VARIANT)) void foo() { std::cout << "The name is: " << BOOST_PP_STRINGIZE(NAME) << '\n'; } --- Any workaround? I'm using Boost from cvs at RC_1_34_0 and g++ 4.0.2 under OpenSuse 10. / Johan

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Comments for Filesystem Library Proposal for TR2 (N1975)
by Daniel Krügler 28 Jun '06

28 Jun '06

Hello! One week ago I wrote a list of comments to the above mentioned proposal provided by Beman Dawes to his email address <mangled_address>bdawes at acm dot org</mangled_address> given in the public paper http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n1975.html Since I got no answer, I assume that the mail got lost due to filter barriers or something else. Is someone aware whether the above mentioned address should be still valid? I apologize for the noise in this group, but currently I'm not able to use either comp.std.c++ or comp.lang.c++.moderated due to news group rearrangements in our company to address this issue there and have hopes that Beman Dawes might read this group ;-) Thanks for your patience, Daniel Krügler

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shared_ptr in a boost::any
by Thomas Matelich 28 Jun '06

28 Jun '06

I use boost::any for sending data to my thread's command queue, and I need to send a shared_ptr in. I'm looking for any one to tell me this is fine or bad. Based on my understanding of boost::any I think it will be fine, but I'm slightly concerned I'll screw up the reference count somehow. Can anyone confirm or allay my fears? Thanks, Tom

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Re: [Boost-users] [date_time] extract date from string using a list of patterns
by james.jones＠firstinvestors.com 27 Jun '06

27 Jun '06

From: Jason Dolan <jason(a)pcc.com> > Thats why I was looking into it this way, I was hoping not to have to > create my own parser. I'm actually kinda of surprised that there isn't > a open source natural language date string parser out there already. Maybe take a look at the source from the GNU "at" command? It would be in C, but might yield some useful ideas. HTH, - James Jones Administrative Data Mgmt. Webmaster 375 Raritan Center Pkwy, Suite A Data Architect Edison, NJ 08837

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still problems with has_xxx and shared_ptr...
by Ovanes Markarian 27 Jun '06

27 Jun '06

Hello all! Sorry to disturb again... I have the following code: namespace detail { BOOST_MPL_HAS_XXX_TRAIT_DEF(element_type) BOOST_MPL_HAS_XXX_TRAIT_DEF(value_type) BOOST_MPL_HAS_XXX_TRAIT_DEF(type) BOOST_MPL_HAS_XXX_TRAIT_DEF(type_t) } struct B1 {}; int main() { typedef boost::shared_ptr<B1> ptr_t; typedef mpl::if_c < detail::has_type<ptr_t>::value , mpl::int_<0> , mpl::if_c < detail::has_element_type<ptr_t>::value , mpl::int_<1> , mpl::if_c < detail::has_value_type<ptr_t>::value , mpl::int_<2> , mpl::if_c < detail::has_type_t<ptr_t>::value , mpl::int_<3> , mpl::int_<-1> > > > > type_id; type_id just_for_debug_an_instance; } MSVC 8.0 debugger shows for just_for_debug_an_instance the following type: boost::mpl::if_c<1,boost::mpl::int_<0>,boost::mpl::if_c<1,boost::mpl::int_<1>,boost::mpl::if_c<1,boost::mpl::int_<2>,boost::mpl::if_c<0,boost::mpl::int_<3>,boost::mpl::int_<-1> > > > > How is it possible, if I really can find in the shared_ptr template class the following typedefs: public: typedef T element_type; typedef T value_type; typedef T * pointer; typedef typename detail::shared_ptr_traits<T>::reference reference; For me it is really unclear why does: detail::has_type<ptr_t>::value has the value 1 in the first static if statement? I looked through the shared_ptr template class and found nowhere the 'type' typedef, function, or anything else, what could be evaluated by has_value. Any help would be really apreciated. Many Thanks, Ovanes Markarian

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Re: [Boost-users] boost 64bit support on windows x64 on amd64 hardware
by Sohail Somani 27 Jun '06

27 Jun '06

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Chu-Ming Ng > Sent: Tuesday, June 27, 2006 1:42 AM > To: boost-users(a)lists.boost.org > Subject: [Boost-users] boost 64bit support on windows x64 on > amd64 hardware > > > Hi, > > I am porting some code that uses boost from 32-bit to the > 64-bit platform and > would like to know if the boost library supports this platforms. I don't know about officially, but I haven't had any problems on 64 bit.

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inspecting templates and boost::is_pointer
by Ovanes Markarian 27 Jun '06

27 Jun '06

Hello all, I am trying to specialize boost::is_pointer so, that it can determine if a type is a pointer wrapper (shared_ptr, auto_ptr, weak_ptr). Does anybody has ideas how this can be done? May be it would be possible to handle if e.g. one can determine if a class/struct has some typedef inside: template<...> class shared_ptr { typedef ... element_type; }; class some_other_class { typedef ... type; }; class some_other_class2 { //no typedef... }; Somehow I am not certain if I am on the right path. My problem is that I have a variant container type with different types. One could access a value using -> operator. The operator returns the pointer to the value. But if this value is a pointer (that can be determined by boost::is_pointer type trait) it should return the pointer and not pointer to pointer value. Now what happens if I store shared_ptr or any other type which overload -> operator? This will result in compiler error, because the compiler tries to access member of the pointer to pointer and not of the pointer instance. Is there may be a way to determine if the member access operator is overloaded? What if -> operator is defined in the base? And what if child class inherits base as protected or private? The other solution would be to force every user to write a specialized class is_pointer for every type stored in variant, but this would be not so nice. With Kind Regards, Ovanes Markarian

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Re: [Boost-users] function traits
by Gottlob Frege 27 Jun '06

27 Jun '06

> > From: David Abrahams <dave(a)boost-consulting.com> "Ovanes Markarian" <om_boost(a)keywallet.com> writes: > > > Does anyone know if it possible to determine if a class > > overloads a certain function _where_ the return type is unknown. > > > > An example is the -> operator. It can return any type. My question > > is: is it possible to determine at compile time if some type > > overloads the -> operator, without knowing the return type when this > > operator is overloaded? > > That would only be possible if -> could be a free function, but IIRC > it is required to be a member function... so the answer is no. > > You can do it for any function that can be implemented as a non-member > (see e.g. boost/detail/is_incrementable.hpp). > > Also, if your end goal is still something like is_pointer_like<T>, instead of detecting operator->, you might be able to use the same techniques as is_incrementable to detect operator * (unary) - ie implement is_dereferenceable<T>. Would it be OK to assume is_pointer_like<T> '==' is_dereferenceable<T> ? Tony

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[date_time] extract date from string using a list of patterns
by Jason Dolan 27 Jun '06

27 Jun '06

I'm looking to take a string and convert it to a date. The only problem is the string can be one of many patterns. i.e. ("%Y%m%d", "%Y-%m-%d", "%d/%m/%Y", etc...). It is also possible that the given string will fail all pattern matches, and thus return false. Can anyone give me an example of how to do this? I know you need to use the date_input_facet, but I am VERY new to boost and can't get it to work. Thanks! -Jason

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