2008/10/21 Jeremy Pack :

Oliver, It depends on what you need the factories to do. Could you describe your use case in more detail? Boost.Extension is for using factories to create objects of classes declared in shared libraries. Jeremy Pack

Hi Jeremy, During the last weeks I've spend some hour on boost.extension. Organizing factories is what boost.extension is all about at the moment. But I think means for portable loading of DSO (Dynamic Shared Objects) are worth a project on its own. Consider this structure - boost.dso - portable dlopen - convenience classes for resource handling - boost.extension - factory pattern - reflection pattern boost.dso will IMHO be suitable for many developers out there having their own factories running, but like to have a well tested and portable dlopen (aka. LoadLibrary on MS Windows). Providing this needs a heavy testing harness which will take a notable amount of developer time. boost.extension itself can concentrate on how to plug and organize loaded code into an application. What do you think? -- Maik

Jeremy Pack schrieb am Donnerstag 23 Oktober 2008 um 18:50:

1 - The shared_library and type_map classes handle much of what you want for DSO. I'm still working on a few convenience functions for the shared_library class, and working on adding some safety mechanisms to help avoid problems with binary incompatibility. Is there any specific functionality you'd like to see that may not be there?

Just being more portable and having it's own testing harness which doesn't use any of the factory part of boost.extension.

2 - There are very few interdependencies between classes in the library. Many of the classes require either the type_map class or the type info functionality, but there are few, if any, other interdependencies. This means that the library could be split up well in quite a number of ways. I hope to resolve the question of whether or not to split the library during a pre-review process.

If the DSO part lives in its own directory it is easier to identify its independency. I like to see boost.extension pops up on top when someone searches for "C++ portable dlopen LoadLibrary" or "c++ dso", so as much developers as possible feel boost being a good place to contribute to C++ DSO handling, even if they are not interested into the factory part. If the DSO part gets bigger and bigger, I suggest to make it an separate lib. Greetings, -- Maik

I have a set of classes, each of them being a subclass of a base class. I need an array of subclasses, and I know which one to instantiate thanks to a numeric or litteral ID. So, I think the solution which fits my needs is Tobias Schwinger's Boost.Functional/Factory library. Thanks for all y our quick answers. Olivier 2008/10/21 Stjepan Rajko

On Mon, Oct 20, 2008 at 2:32 PM, Olivier Tournaire wrote:

...

Hi all,

I am wondering if a factory exists in boost. Any answer ?

Tobias Schwinger's Boost.Functional/Factory library was accepted into boost last year (http://lists.boost.org/boost-announce/2007/12/0161.php), but I don't think it has made it to trunk yet (I think you can get it from the vault). This library provides functional object adapters for both dynamic allocation of objects as well as value-based construction.

I have found it relatively straightforward to use this library in concert with Boost.Function and Boost.Bind to construct simple factory classes that can allocate objects based on provided keys. If that's the sort of factory you are looking for, I recommend Tobias's library.

Kind regards,

Stjepan _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

On Tue, Oct 28, 2008 at 3:01 PM, Olivier Tournaire wrote:

Hi Stjepan,

A week ago, when I read your message, I was able to find the Tobias' lib. However, today, I cannot find it anymore ... Do you have a link to help me ?

http://www.boostpro.com/vault/index.php?&direction=0&order=&directory=X-Files Best, Stjepan