I'm trying to implement a runtime reflection module, and am
having some issues with figuring out the function pointer to
invoke an interface method on a class that derives from the one
that implements the interface.
For example, given the following code, we can call an interface
function using a delegate: http://pastie.org/8255612 - but even
with the derived instance passed in it will invoke Bar's
implementation as we're using Bar's object.Interface instance and
thus vtable. I figured typeid(DerivedBar).interfaces would
return it's own Interface instance for DerivedBar, but it returns
an empty array and instead Bar's has to be used.
The ABI page doesn't seem to mention much about inheriting from a
class that implements an interface and overrides it's functions.
Is there a way to get the function pointer to the overridden
version of foo on DerivedBar using Bar's object.Interface
instance for Foo? How does the compiler know what method to call
in this situation?
I'm hoping to accomplish the below without storing data for
DerivedBar:
auto metadata = createMetadata!Foo;
DerivedBar instance = ... // DerivedBar is not known at
compile-time.
metadata.invokeMethod("bar", instance, params);
