Re^3: on the fly reference to subroutine output

[Anonymous Monk]

The incorrect assumption here is that sub1 is returning an array.

In perl5, subs can return scalars or lists. Since it's not returning a (scalar) reference to an array, the only option is to store the list into a (possibly anonymous) array and pass a reference into sub2

tjd

[thirdm]

Ah, I'm always forgetting this.

But underneath, is there a chance at some kind of return value optimization? Say if you have...

sub1 {
...
   return @a;
}

$r = [sub1];

Even if it's officially turning the values of @a into a list en route to copying them into the array that the brackets create a reference to, could perl not notice @a is no longer needed otherwise and instead simply make [sub1] be \@a behind the scenes? It would be neat if you could write sub1 that way instead of making it return \@a even if you anticipated the copy to be expensive.