On Monday, 1 June 2015 at 16:40:38 UTC, Marc Schütz wrote:
On Monday, 1 June 2015 at 15:45:11 UTC, Andrei Alexandrescu
wrote:
On 6/1/15 5:50 AM, "Marc =?UTF-8?B?U2Now7x0eiI=?=
<[email protected]>" wrote:
On Monday, 1 June 2015 at 04:43:20 UTC, Andrei Alexandrescu
wrote:
Also, object with destructors need to have more restrictions:
S {
~this();
}
void foo() {
S s;
if(condition)
bar(s);
// <- should we run the destructor here?
}
This can either be solved by making such cases non-eligible,
or by
"remembering" whether an object was moved using a hidden
boolean
variable. AFAIK the latter is incidentally the solution Rust
chose.
This has been solved, we have move which obliterates the
source with .init.
Huh? What does that have to do with the current topic?
The question is not what should happen when someone does a
conditional _explicit_ move, but whether a move should be done
_implicitly_ by the compiler given the above constellation, and
how it deals with the destructor if yes.
Obviously, only Andrei can say for sure what he meant, but I
would guess that he was suggesting that in the case of
if(condition)
bar(s);
it would set s to S.init when it's moved for the call to bar so
that the destructor can be run when s exits scope regardless of
which branch was executed - though that does mean that the
destructor is run twice when bar(s) is called (once inside of Bar
for the original value and once for the init value) - so while
that solution is correct and straightforward, I'm not sure that
it's the best one.
- Jonathan M Davis
