On Friday, 15 October 2021 at 17:22:52 UTC, Tejas wrote:
On Friday, 15 October 2021 at 06:52:41 UTC, Kostiantyn Tokar
wrote:
On Thursday, 14 October 2021 at 17:53:57 UTC, Tejas wrote:
Maybe DIP 1040 will automatically solve that?
last use of objects that is a copy gets elided into a move
That is what it states, so maybe this one time, the problem
will go away just by waiting?
It would be great, but still, if I understand correctly, it is
not perfect solution for lvalue arguments. Consider, e.g.,
`Tuple` construction from an lvalue. With this DIP and current
state of constructor it will be 1 copy (from argument to
constructor's parameter) and 1 blit (from parameter to the
field). With `auto ref` and forwarding it would be 1 copy from
parameter to the field and no blits. Forwarding saves one blit
per indirection, i.e., for `tuple` it would be 2 blits vs. 0.
Yeah blitting as a concept will go away from D(will only stay
for backwards-compatibility)
Copy constructors already made blits obselete, move
constructors will remove the need for post-blits and finish the
job and the second case that you talked about will become the
default
Now I get it. If this DIP will be accepted, I just have to
provide move constructor/assignment for my types and forwarding
would work. It sounds really great. If so, there is no need to
rewrite half of Phobos to support forwarding. And it even covers
last use of a field of an aggregate! Hope it will be accepted.
Paul, Tejas, thank you for answers.
