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digitalmars.D.learn - Questions on accessing D objects from C

I like the way my code looks written in D but I need to keep my C safety net.
it is important for me to be able to use *all* my code written in D.

I have only very basic literacy in C++. So I have some questions that might be 
obvious to someone from a C++/OOP background.

What is the point of object.vtbl[]? It's per type info so you know everything 
about member functions at compile time and function names appear to show up in 
the object file mangled in a way that makes sense for virtual functions. Is 
there something dynamic happening to vtbl[]? I can imagine use in getting a 
pointer to an unknown object and then searching it's vtbl[] for a destructor... 
but there doesn't seem to be enough info available to do that.

Will the present behavior of extern(C) on classes be part of the specification
of D?

   class Foo{
     int func1();
     int func1(int i);

Right now this appears to put Dmangled function names with C calling
with a pointer to the object to operate on as the first parameter.

To work with my object from C:
extern int _D6FooMod3Foo5func1UZk(void*);
extern int _D6FooMod3Foo5func1UkZk(void*,int);
   void* foo;
   int i;

   foo = get_allocated_object_pointer();
   i = _D6FooMod3Foo5func1UZk(foo);

With a few #defines to clean up the mangled function names I have a sane 
interface into D objects. Can I depend on this behavior?


Traveler Hauptman
Sep 20 2005