On 7/24/2015 11:35 AM, Jacob Carlborg wrote:
On 2015-07-24 08:42, Walter Bright wrote:
It's a good question. And the answer is, the top level function does not
list every interface used by the call tree. Nested function calls test
at runtime if a particular interface is supported by an object, using
dynamic casting or QueryInterface() calls. It's fundamentally different
from traits and concepts.
If you have an interface and then doing a dynamic cast then you're doing it
wrong. Yes, I know that there are code that uses this, yes I have done that too.
Dynamic cast is no different from QueryInterface(), which is how it's done, and
the reason is the point of all this - avoiding needing to enumerate every
interface needed by the leaves at the root of the call tree.
