On 04/10/18 11:16, Paolo Invernizzi wrote:
While I want to thank you both, about the quality of this thread, what
kind of "consequences that go beyond what I think you understand" are
you thinking of? Can you give an example?
Assuming I understand Stanislav's proposal correctly (an assumption I'm
reluctant to make, hence my request for something more formal), it boils
down to two points:
* move the data as part of the call hook rather than before
* Use a different name and signature on the hook function
The first one we can argue for or against. My original proposal was
phrased the way it was precisely because that's the way copying works in
D (copy first, patch the data later). About a week after I submitted it,
Andrei came forward with requesting to move to copy constructors.
The second, to me, is a non-starter. The only way you'd get a function
who's signature is:
void someName(Type rhs);
But which actually maintains rhs's address from before the call is if
the compiler treats "someName" as a special case, and emits code which
would normally be emitted for the function:
void someName(ref Type rhs);
That's why it was important for me to clear up whether there is *ever* a
case in the current language where that happens (answer: only by
accident, which is the same as saying "no").
So to get that to work, you'd need to insert a special case into the ABI
of the language: if the function's name is someName, treat it differently.
At this point, you might as well call a spade a spade, and just give the
function that signature explicitly. s/someName/opPostMove/, and you get
DIP 1014 (as far as point #2 is concerned).
Shachar
