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[ANN] Interfaces Library
by Jonathan Turkanis 27 Jan '05

27 Jan '05

I am pleased to announce the much anticipated (by me) release of a preliminary version of my interfaces library. The download page and online docs are here: http://www.kangaroologic.com/interfaces/ (For fun, click on "Online Documentation" and then on the Boost logo.) The library is an implementation of Christopher Diggins's proposal to add interfaces to C++, which was posted on comp.std.c++ early last year and later was described in the C/C++ User Journal. It provides a macro-based Interface Definition Language (IDL) which can be used to define C++ class types called interfaces. An interface is a lightweight value type associated with a set of named function signatures. An interface instance can be bound at runtime to any object which implements the interface, i.e., to any object of a type with accessible non-static member functions having the same name and signature as the set of functions associated with the interface. The functions of the bound object can then be invoked through the interface instance using the "dot" operator. Binding is completely non-intrusive: the object's type need not declare any virtual functions or derive from any particular base class. Current applications include: * Non-intrusive dynamic polymorphism - interfaces can often be used in place of abstract base classes, and are sometimes much faster. * Dynamic inheritance - allows function calls to be forwarded automatically to an object specified at runtime. * Smart Interface Pointers - smart pointers which can manage the lifetime of any object whose type implements a given interface. * Smart References - like smart interface pointers, but the managed object is accessed using the dot operator. * The Object Oriented Template Library, a project in the initial stages of development, by Christopher Diggins. Planned future applications include: * Runtime reflection - will allow an interface's functions to be enumerated and looked up by name at runtime * Aspect Oriented Programming as described in a August 2004 Dr. Dobb's Journal article by Christopher Diggins. Possible future applications include: * Integration with component architectures such as COM and CORBA. * Boost.Names - by abstracting the various uses of identifiers in C++ into preprocessor generated types called names, C++ classes and functions can be constructed in a straightforward manner using template metaprogramming. Best Regards, Jonathan

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[ANN] range algorithms and adaptors
by Eric Niebler 27 Jan '05

27 Jan '05

I just uploaded to the boost-sandbox a set of range-based algorithms and adaptors. The algorithms are based on container_algo.hpp from the sequence_algo library (Thorsten Ottosen, Jeremy Siek, Vladimir Prus). I have reimplemented them on top of Boost.Range, and changed the modifying algorithms to work with ranges that are physically const but logically non-const (such as std::pair<char*,char*> const). I have also implemented range adaptors, which are built on top of Boost.Range and the iterator adaptors in Boost.Iterator. There are transform, filter, reverse and indirect range adaptors. They combine with the range algorithms and with BOOST_FOREACH. Consider the following which takes a list of Widget pointers and finds a Widget which is visible and that is named "This Widget": list<Widget*> widgets = ...; list<Widget*>::iterator = find( widgets | indirect | filter(bind(&Widget::Visible,_1)) | transform(bind(&Widget::Name,_1)) , "This widget" ).base().base().base(); And consider the following, which loops over a vector in reverse order: vector<string> strings = ...; BOOST_FOREACH( string & str, strings | reverse ) { cout << str << '\n'; } The code is in boost-sandbox at boost-sandbox/boost/range_ex. I have also put a range_ex.zip in the file vault at: http://boost-sandbox.sourceforge.net/vault/index.php?directory=eric_niebler No docs or tests yet. This is a work in progress. Feedback welcome. -- Eric Niebler Boost Consulting www.boost-consulting.com

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What is the status of associative vector framework?
by ION_G_M 27 Jan '05

27 Jan '05

Hello to all, While developing Boost Shmem, I needed an associative container to store data in shared memory, and the easiest one to develop was an ordered vector. For this, I'm using a slightly modified version of Loki's AssocVector (just added reserve() and capacity() members to adjust memory and boost performance in some cases). Reading Boost Files section, I've seen an associative_vector directory containing a preliminary version of this class and related mails, but I don't see any more references to this class since 2002. In the Formal Review Schedule page it is not listed but I can see some review mails googling around so I was asking if this library was abandoned for any reason. I think that this king of "flat" associative containers are very useful, since they are normally faster than std::set/map in lookups and more memory friendly, specially for small types, since normally a tree like structure imposes an overhead of 3 pointers and an integer per node. That without counting that memory allocation for a vector has far less fragmentation when using std::allocator. Is the library still alive? Is anyone insterested in these classes? What I propose is a std::set/map/multiset/multimap like interface on an ordered vector, without more advanced functions, perhaps with added reserve/capacity interface to optimize memory allocation when the number of elements is known beforehand. Best regards, /Ion ---EOF---

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[Boost-bugs] [ boost-Bugs-1110443 ] boost::uniform_on_sphere in not uniform on sphere
by SourceForge.net 27 Jan '05

27 Jan '05

Bugs item #1110443, was opened at 2005-01-27 10:38 Message generated for change (Tracker Item Submitted) made by Item Submitter You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=107586&aid=1110443&group_… Category: random Group: None Status: Open Resolution: None Priority: 5 Submitted By: USU ACM (usu_acm) Assigned to: Jens Maurer (jmaurer) Summary: boost::uniform_on_sphere in not uniform on sphere Initial Comment: It's clear that your previous (1.29) and current verisons (1.32) has no really uniform point distribution on sphere. This fact can be proved by observation that distributions of all coordinates are independent on each other. For example for 3D-sphere really uniform distribution is given by Euler angles (x, arcsin(2t - 1)), where x is uniformly distributed random value on [0..2*pi]. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=107586&aid=1110443&group_… ------------------------------------------------------- This SF.Net email is sponsored by: IntelliVIEW -- Interactive Reporting Tool for open source databases. Create drag-&-drop reports. Save time by over 75%! Publish reports on the web. Export to DOC, XLS, RTF, etc. Download a FREE copy at http://www.intelliview.com/go/osdn_nl _______________________________________________ Boost-bugs mailing list Boost-bugs(a)lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/boost-bugs

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Review Manager Needed - Wave Review
by Tom Brinkman 27 Jan '05

27 Jan '05

The Wave Library is ready to review by the boost group. Hartmut indicated that he would like to start around January 31, 2005. Are there any boost members that are familiar with his library and would like to volunteer to be the review manager. The library can be downloaded at: http://cvs.sourceforge.net/viewcvs.py/boost-sandbox/boost-sandbox/libs/wave/ Contact me if you would like to volunteer. Tom Brinkman Review Wizard __________________________________ Do you Yahoo!? Read only the mail you want - Yahoo! Mail SpamGuard. http://promotions.yahoo.com/new_mail

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Questions on boost::filesystem
by Ami Tavory 26 Jan '05

26 Jan '05

Hello, I have some questions encountered while attempting to extend the boost::filesystem library (BTW, thanks to all involved with this excellent library). I often need to do something with all files matching certain criteria which reside (recursively) in subdirectories matching some (probably different) criteria. E.g., I might want to list all *.hpp files in all subdirectories of 'develop', or search for the first *.cpp file in all subdirectories of "my_proj" excluding "my_proj/bin". Using the boost::iterator library (BTW, thanks to all involved with this excellent library as well), I built a recursive_directory_iterator, parameterized by a functor indicating whether to expand a subdirectory, and a filter iterator, parameterized by a functor indicating whether to retain an entry with a given path, which filters the sequence formed by some other underlying iterator (e.g., recursive_directory_iterator, in this case). This led to two questions: 1. Does the library already include similar functionality? (I couldn't find any;) If not, are there any pitfalls involved? 2. There are (at least) two ways to implement recursive_directory_iterator, which display a memory/time tradeoff: (a) using a stack of boost::filesystem::directory_iterator, and (b) using a boost::filesystem::directory_iterator (for the current subdirectory) and a boost::filesystem::path (for the (parent) subdirectory entry to which to return once the current subdirectory is exhausted). Consequently, I made this too a policy of recursive_directory_iterator. Version (b), however, throws an exception when trying to iterate over a subdirectory "foo!": specifically, I can't assign "foo!" (or any name including '!') to a boost::filesystem::path object, although it seems that my filesystem (on Windows XP) finds "foo!" an acceptable name for a subdirectory. Should I be using boost::filesystem differently? Many Thanks, Ami

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[ANN] QuickBook 1.0 now in boost/tools
by Eric Niebler 26 Jan '05

26 Jan '05

Joel de Guzman and I are happy to announce the general availability of QuickBook, the mindlessly simple way to generate BoostBook-based documentation. The official home for QuickBook is now boost/tools/quickbook. <<What is QuickBook?>> QuickBook is a WikiWiki style documentation tool geared towards C++ documentation using simple rules and markup for simple formatting tasks. QuickBook extends the WikiWiki concept. Like the WikiWiki, QuickBook documents are simple text files. A single QuickBook document can generate a fully linked set of nice HTML and PostScript/PDF documents complete with images and syntax-colorized source code. Features include: * generate BoostBook xml, to generate HTML, PostScript and PDF * simple markup to link to Doxygen-generated entities * macro system for simple text substitution * simple markup for italics, bold, preformatted, blurbs, code samples, tables, URLs, anchors, images, etc. * automatic syntax coloring of code samples * CSS support For point of reference, the entire set of xpressive's documentation at: http://boost-sandbox.sf.net/libs/xpressive was generated from a the single text file: http://tinyurl.com/6h464 (full link: http://cvs.sourceforge.net/viewcvs.py/*checkout*/boost-sandbox/boost-sandbo…) Up-to-date documentation for QuickBook can be found in CVS at boost/tools/quickbook/index.html . -- Eric Niebler Boost Consulting www.boost-consulting.com

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Re: [boost] Re: [Serialization] of pointers into a vector
by JOAQUIN LOPEZ MU?Z 26 Jan '05

26 Jan '05

----- Mensaje original ----- De: Robert Ramey <ramey(a)rrsd.com> Fecha: Martes, Enero 25, 2005 10:33 pm Asunto: [boost] Re: [Serialization] of pointers into a vector > This is a currently known problem with the library. It only became > apparrent with the implementation of serialization for indexed set. > > The problem arises because the objects are deserialized to a temporary > variable then moved into the collection. So the pointers are not > going to > point to objects final resting place. > This can be circumvented if one's willing to accept making intrusive changes to the element type. The following is a sketch of the tecnhique (caveat, not compiled): template<typename Derived> class retrackable { private: friend class boost::serialization::access; template<class Archive> void serialize(Archive&,const unsigned int) { // do nothing } }; class object:public retrackable<object> { ... template<class Archive> void serialize(Archive&,const unsigned int) { // serialize as usual } } class foo { private: std::vector<object> v; object* po; // po points to some element of v friend class boost::serialization::access; BOOST_SERIALIZATION_SPLIT_MEMBER() template<class Archive> void save(Archive& ar,const unsigned int version)const { ar<<v; for(std::vector<object>::const_iterator it=v.begin(),it_end=v.end(); it!=it_end;++it){ ar<<static_cast<const retrackable<object>&>(*it); } ar<<static_cast<retrackable<object>*>(po); } template<class Archive> void load(Archive& ar,const unsigned int version) { ar>>v; for(std::vector<object>::iterator it=v.begin(),it_end=v.end(); it!=it_end;++it){ ar>>static_cast<retrackable<object>&>(*it); } retrackable<object>* pro; ar>>pro; po=static_cast<object*>(pro); } }; Of course, an extension to Boost.Serialization would be better --something along a facility to instruct the serialization lib to change the tracking address of an object when this is moved around. HTH, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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Re: [boost] Re: Re: [Serialization] of pointers into a vector
by JOAQUIN LOPEZ MU?Z 26 Jan '05

26 Jan '05

----- Mensaje original ----- De: Robert Ramey <ramey(a)rrsd.com> Fecha: Miércoles, Enero 26, 2005 1:12 am Asunto: [boost] Re: Re: [Serialization] of pointers into a vector > > JOAQUIN LOPEZ MU?Z wrote: > > ----- Mensaje original ----- > > Of course, an extension to Boost.Serialization would > > be better --something along a facility to instruct > > the serialization lib to change the tracking address > > of an object when this is moved around. > > > > I don't think it will be all that hard once its apparent what the > problemis. (Of course that's what I always think - that's my problem) > > my current thinking is to implement something like > > template<class Archive, class T> > common_iarchive<Archive>::move(T & dest, T & source) > > which would do the assignment and update the tracking information. > Then use > it in the de-serializaton of all the collections. This particular interface, if I'm not wrong, is of no use for the collections case, since the assignment is done internally by the container. At least, you need a similar facility that only does the tracking thing: template<class Archive, class T> common_iarchive<Archive>::move_track(T * dest, T * source) // no assignment While we are at it, it could be good to have something along this line for a different but related situation: sometimes it can be necessary to serialize pointers to objects which are *not* serialized themselves (i.e. they are reconstructed by some other means.) This can be achieved with something like: template<class Archive, class T> common_iarchive<Archive>::set_track(T * p) which allows the object pointed by p to be tracked (that is, pointers to it can be serialized) without attempting to load/save the object itself. Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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BOOST_PP_SEQ_ENUM
by Arkadiy Vertleyb 25 Jan '05

25 Jan '05

Hi all, Is BOOST_PP_SEQ_ENUM broken? I can't use it with VC71. It expands to something like: BOOST_PP_SEQ_ENUM_3[space](x)(y)(z) and stops here, probably because of the space. Shouldn't the current definition: # define BOOST_PP_SEQ_ENUM(seq) BOOST_PP_CAT(BOOST_PP_SEQ_ENUM_, BOOST_PP_SEQ_SIZE(seq)) seq be replaced with something like: #define BOOST_PP_SEQ_ENUM(seq) BOOST_PP_SEQ_CAT((BOOST_PP_SEQ_ENUM_)(BOOST_PP_SEQ_SIZE(seq))(seq)) Regards, Arkadiy

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