On 12/27/17 6:28 PM, Tofu Ninja wrote:
On Sunday, 24 December 2017 at 05:21:44 UTC, Tofu Ninja wrote:
I didn't get any response in learn for this so I will ask it here.
TypeInfo_Class.interfaces[n].classinfo has TypeInfo_Class and not
TypeInfo_Interface?
Is this correct? Or is it a bug?
Doesn't make much sense to me.
Also the following code prints false so there are some consequences to
this.
# # ]]]]]]]]]]]]
import std.stdio;
void main(string[] args) {
writeln(typeid(c).interfaces[0].classinfo == typeid(i)); // false
}
interface i {}
class c : i {}
What is the proper way to handle this mismatch?
Is this mismatch intended or just some implementation detail?
Peoples thoughts on this?
I guess I will just not get an answer to this, seems like just some
weirdness of D that will just stick there. The typeinfo system seems
really half baked and really provides very little in terms of usefulness.
I'm not even sure why TypeInfo_Interface exists. It seems to be a thin
wrapper over its TypeInfo_Class member `info`. TypeInfo_Class itself has
an overridable `info` member which is never overridden, so I'm not sure
what the purpose of that is either.
Looking at the implementation of TypeInfo_Interface, it appears that the
only reason to have it, is to allow using interfaces as hash keys. But
the blunt casting there, I don't think is right. Not all interfaces can
be cast to Object.
I'll note that opEquals is also implemented incorrectly.
IMO, TypeInfo_Interface should be derived from TypeInfo_Class, and
simply override the equals/getHash/compare functions. Then change the
type of 'classinfo' inside the Interface struct to TypeInfo_Interface.
The compiler needs to be updated for this of course.
So in short, I think there are bugs here, but probably not what you
expected.
-Steve
