Edward Diener wrote:
Yes, I am interested in it. It appears to provide a way to do reflection on a limited basis by using a name to create an object.
I am not sure if this really compares to "reflection" (and introspection?). I am simply using a map std::map<std::string, boost::any >, where the any part holds a pointer to a constructor function. The string on the other side is a composite of the class name and typeid(FN).name(), where FN is the signature of the ctor function. If you think using the RTTI of C++ == reflection then your assumptions are correct.
Hajo Kirchhoff in his LitWindow library also provides a way to do reflection based on names although I do not believe he has the ability which you have to dynamically create objects based on names.
I was not aware of this. Thank you for the pointer.
The only nit I have to pick is calling your implementation a virtual constructor lib. I do not see where polymorphism comes into play in the actual construction of the objects from its name. Perhaps a "name constructor lib" would be more accurate.
Hmm, I was already considering this, but look at it a different way: What is the sense of beeing able to construct an object of which you do not know anything? You won't be able to call a single function! So you definitely need at least an abstract base class that defines the common interfaces. And this is where polymorphism comes into play. I would even say that the "covariant return types" are at the core of my implementation. Now my implementation allows to instantiate any derived class. This is why it is called "virtual constructor". Also it is not me who coined this wording. As I already mentioned I was reading Stroustrups book and his explanation of the term "virtual constructor" inspired me to my implementation. (But having it called dynamic_new reflects your concerns a little I think.) Roland