On 18/09/2012 21:10, Nick Sabalausky wrote:
On Tue, 18 Sep 2012 15:43:37 +0200
"monarch_dodra" <[email protected]> wrote:
On Tuesday, 18 September 2012 at 12:06:15 UTC, Steven
Schveighoffer wrote:
There is another reason to avoid this.
Note that if I have two consecutive blocks of memory:
0...4
and
4...8
If we define an array that points to the first block as a
pointer to 0 and a pointer to 4, then that array also
effectively points at the second block (4...8). The way the GC
works, it will not release the second block as long as you have
a pointer to the first, even though the second pointer is not
technically pointing at the block.
-Steve
That's a good point. I also shows another danger of ptrEnd: Not
only is it not a reference to the current range, it could *also*
be a reference to an un-related range.
Does the above not also mean that the second array's 'ptr' prevents the
first array from being garbage-collected?
In any case, maybe the heap leaves gaps (perhaps if it has to insert
metadata), so this is a non-issue anyway?
FWIW, a ptrLast would avoid that (ie, arr.ptrLast == &arr[$-1])
That would make the problem worse for zero-length arrays though. Don't
forget the corner-cases :)
