- Boost-users - lists.boost.org

Re: [Boost-users] Translating an absolute path to a path relative
by Gottlob Frege 31 Oct '05

31 Oct '05

> > Date: Mon, 31 Oct 2005 09:55:57 -0300 > From: Hermann Rodrigues <hermann.rodrigues(a)gmail.com> > Subject: [Boost-users] Translating an absolute path to a path relative > to the current directory > To: boost-users(a)lists.boost.org > Message-ID: > <497dfc460510310455j1bd56615peffd2f6040fe849e(a)mail.gmail.com> > Content-Type: text/plain; charset=ISO-8859-1 > > Hi, > > I am running into the following problem these days: > > I need to translate an absolute path to a path relative to the current > directory on Windows. The translation process need to include all > required ".." directory specifiers in the path to make sure it can be > accessed from the current directory. > > Have you tried the Windows functions such as PathRelativePathTo, and its compliment PathCombine?

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[BUG] missing references in docs on web site (threads)
by Ross Boylan 31 Oct '05

31 Oct '05

While reading the web pages for the threads library I noticed some missing references. I don't know if they reflect a problem with the documentation source or a problem with the processing converting the source into html (if there was any such processing). I did check the html source of teh web pages to verify that it wasn't a display problem with my browser. http://boost.org/doc/html/threads.html#id1357380 In "Potentially non-thread-safe functions" this appears: "It is possible to write thread-safe implementations of these by using thread specific storage (see boost::thread_specific_ptr), and several C++ compiler vendors do just that. The technique is well-know and is explained in ." The reference at the end is missing. I thought I saw another example like this in the threads doc, but can't find it now. Also, the quote from Brinch Hansen at the end of http://boost.org/doc/html/threads/rationale.html doesn't indicate the source (though one could at least guess the article from the bibliography, though he's co-author of another one in the bibliography).

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Re: [Boost-users] [Multi-Index] composite_key problems
by Andreas Volz 31 Oct '05

31 Oct '05

Am Mon, 31 Oct 2005 18:14:00 +0100 schrieb JOAQUIN LOPEZ MU?Z: > // lookup by (A,B); > > es.find(make_tuple(a,b)); > > // lookup by A alone > > es.find(make_tuple(a)); > > // lookup by B alone > // note get<1> retrieves the second index. > > es.get<1>().find(b); > > Is the issue clearer now? If not, please tell me > so and I'll try to explain myself a bit further. A little clearer, but not at all. I'm really new to Boost, so I doesn't understand all. The questions seems to by stupic, but how could I access the data looked up by B alone? What should I assign to the left? > ??? = es.get<1>().find(b); An iterator or what else? There was a print_out_by_name function in docs that I tried to adopt, but I failed. And the compile errors are not very helpfull. As normal with template programming :-( regards Andreas

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[Boost.filesystem] Support of Unicode OS ?
by Marc Viala 31 Oct '05

31 Oct '05

Hi, I would like to know if there are some implementations of "Boost.filesystem" to support Unicode OS like Windows XP? We are involved in a large project, we use Boost libraries intensively, version 1.33, and we are looking forward for this mandatory feature. Thanks in advance for your reply. Marc Viala www.acticm.com <http://www.acticm.com> mailto:mviala@acticm.com <mailto:mviala@acticm.com>

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C++ Connections question
by Elisha Berns 31 Oct '05

31 Oct '05

Ok, So this isn't a Boost.X question, but I have to ask since Dave Abrahams is giving two talks at the C++ Connections conference next week. The question is since the sessions, any session not just Dave's, are either only 60 or 75 minutes max, how informative and in depth can they possibly be? It would appear they are only to whet one's appetite for learning something, but that is precisely my question. Thanks for offering an appraisal whether this conference is really worth the bother. Elisha Berns e.berns(a)computer.org tel. (310) 556 - 8332 fax (310) 556 - 2839

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Re: [Boost-users] downcasting shared pointer
by Bjorn.Karlsson＠readsoft.com 31 Oct '05

31 Oct '05

Hello Faheem, > From: Faheem Mitha [mailto:faheem@email.unc.edu] > > It would be nice if there was some method to downcast the shared_ptr > itself. See http://www.boost.org/libs/smart_ptr/shared_ptr.htm#static_pointer_cast for details on how to do just that. Regards, Bjorn Karlsson

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Implementing lock/unlock with boost::thread
by Johan Torp 31 Oct '05

31 Oct '05

I'm trying to implement a class having a lock and an unlock-method. If several different threads call scoped_lock::lock, what is the effect? class AntiRAII{ public: AntiRAII() : mLock(mMutex, false) {} void Lock() {mLock.lock(); } void Unlock() {mLock.unlock();} private: boost::mutex mMutex; boost::mutex::scoped_lock mLock; }; I cannot find any documentation on the behaviour. The usual usage of scoped_lock is one per thread, which is why I'm sceptical to this approach. How can this be implemented? Is it better to expose the mutex? Regards, Johan Torp

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Re: [Boost-users] [Multi-Index] composite_key problems
by JOAQUIN LOPEZ MU?Z 31 Oct '05

31 Oct '05

----- Mensaje original ----- De: Andreas Volz <lists(a)brachttal.net> Fecha: Domingo, Octubre 30, 2005 8:15 pm Asunto: [Boost-users] [Multi-Index] composite_key problems > Hi, > > I like to build a data structure and like to access it with different > keys, so I try multi_index for this. [...] > I hacked the basic example to get this working. My example compiles, > but if I execute it, I get only warnings: > > probe: /usr/include/boost/multi_index/detail/index_iterator.hpp:107: > typename Node::value_type& > boost::multi_index::detail::index_iterator<Node, > Container>::operator*() const [with Node = > Container>boost::multi_index::detail::ordered_index_node<boost:: > multi_index::detail::index_node_base<learnedMeasure> > Container>>, Container = > Container>>boost::multi_index::detail::ordered_index<boost:: > multi_index::composite_key<learnedMeasure, > Container>>boost::multi_index::member<learnedMeasure, std::string, > Container>>&learnedMeasure::measu > .... more warnings > > I put my example code online. Perhaps someone could take a look in it > and help me to find this problem. > > http://cpp.sourceforge.net/?show=9550 > Hello Andreas, I can't compile your source right now, but from the looks of it I cannot see anything wrong. What compiler are you using? If MSVC++ 6.0 or 7.0, take into account they have non-conformances you must take into account when using Boost.MultiIndex, see http://boost.org/libs/multi_index/doc/compiler_specifics.html Your particular code won't work on either of these compilers due to problems with member<> and composite_key that are addresses in the aforementioned page. Is this the problem? If not, I'll try to get back to you in a couple of days. Best, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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regexp: New problem with trailing - in character class
by Greg Ferrar 31 Oct '05

31 Oct '05

Hi, I've been using Boost regexp library forever, and it's great. But I just grabbed 1.33.0 (trying to get it to compile on 64-bit Windows), and I'm getting an error I never got before: it refuses to allow this regular expression: [a-z-] which is supposed to mean "a lower case letter or a dash". Previous versions of Boost regexp allowed this, and grep allows it, and version 1.33.0 does allow this one: [-a-z] Is this a deliberate restriction? It's causing me lots of problems, because my application has a lot of existing regular expressions which use this syntax. This occurs both on x64 with VC8, and on a pretty standard (and old) 32-bit Linux system. I've hacked around it horribly for now by adding this to the top of regcompA (I use the A posix interface exclusively): // HACK by GMF to fix problem that [a-z-] is not accepted as valid, but [-a-z] is. Fix it by moving the dash. char *p = (char*) ptr; while (*p) { printf("p: %c\n", *p); if (*p == '\\') p++; else if (*p == '[') { char *q = p+1; while (*q && (*q != ']')) { printf("*q: %c\n", *q); q++; } if (*q == ']') { q--; if (*q == '-') { memmove(p+2, p+1, (q-p)-1); *(p+1) = '-'; p = q; } } } p++; } but that's very nasty, and probably doesn't work properly anyway, and I'd sure like to get that out of my production code. Help! Greg

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Using iterator_facade from base class with sub classes
by Daniel Lidström 31 Oct '05

31 Oct '05

Hello! I have implemented the iterator_facade for a base class called DataObject. So now I am able to write things like this: boost::shared_ptr<PxyFileData> file(...); const DataObject& points = file->GetPoints(); int num_points = std::distance(points.begin(), points.end()); //! random access iterator A DataObject acts like a tree structure. Each DataObject holds a vector of pointers to children, which are also DataObjects. Now to my problem: A PxyPoint is a sub class to DataObject, and PxyFileData::GetPoints() returns a DataObject where all the children are PxyPoint's. Now I would like to call a member function, PxyPoint::PutSpCode(const char*), on each of the children, like this: void put_sp_code(DataObject&, const char*); void test() { shared_ptr<PxyFileData> file(...); DataObject& points = file->GetPoints(); put_sp_code(points, "spcode"); } void put_sp_code(DataObject& points, const char* code) { std::for_each(points.begin(), points.end(), std::bind2nd(std::mem_fun(&PxyPoint::PutSpCode), code)); } This does not compile (VC 7.1): c:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\include\algorithm(21): error C2664: 'binder2nd<_Fn2>::result_type binder2nd<_Fn2>::operator ()(binder2nd<_Fn2>::argument_type & ) const': cannot convert parameter 1 from 'DataObject' to 'binder2nd<_Fn2>::argument_type & ' with [ _Fn2=mem_fun1_t<void,TPunkt,const char *> ] and [ _Fn2=mem_fun1_t<void,TPunkt,const char *> ] A reference that is not to 'const' cannot be bound to a non-lvalue c:\projects\GEOW\V12\Test\GeoTest\Model Test\ModelTest.cpp(48): see reference to function template instantiation '_Fn1 for_each<iter,binder2nd<_Fn2> >(_InIt,_InIt,_Fn1)' being compiled with [ _Fn1=binder2nd<mem_fun1_t<void,TPunkt,const char *> >, _Fn2=mem_fun1_t<void,TPunkt,const char *>, _InIt=iter ] (error message formatted with STLTask) Is this possible with our design? I would like to be able to do this without having to create a PxyPointList, that derives from DataObject and only stores PxyPoint's (my guess is that something like that would work with this code). Thanks in advance! Regards, Daniel

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