On 12/24/12 1:49 PM, Jonathan M Davis wrote:
On Monday, December 24, 2012 13:45:10 Andrei Alexandrescu wrote:
The very binding of rvalues to const ref would allow that breakage. We
can't allow that to happen.
But it's only bound for the length of the statement. After that, the binding
can no longer exist (as the binding was a function parameter). And as I
understand it, temporaries only go out of scope once the statement has
completed. So,
foo(bar(min(5, 7)));
wouldn't be a problem no matter what bar or foo did, because no reference to
5, 7, or the return values of any of the functions could be kept.
Actually D's rules are different from C++'s in that regard; Walter
mentioned D is more sanguine about destroying data. I'll check with him.
It's being
able to do
const int& i = foo(bar(min(5, 7)));
which would allow a reference to be kept around, which D disallows.
I now see what you mean, thanks. We need to disallow taking the address
of that ref, but that's already planned.
Andrei
