On Thu, 05 Jun 2014 15:54:33 -0400, Steven Schveighoffer
<[email protected]> wrote:
On Thu, 05 Jun 2014 15:48:09 -0400, Steven Schveighoffer
<[email protected]> wrote:
On Thu, 05 Jun 2014 15:34:13 -0400, monarch_dodra
<[email protected]> wrote:
On Thursday, 5 June 2014 at 19:27:56 UTC, Steven Schveighoffer wrote:
On Thu, 05 Jun 2014 14:47:54 -0400, deadalnix
T[] arr = [ ... ];
arr = arr[$ .. $];
auto garbage = *(arr.ptr);
Believe it or not, this is actually safe.
What do you mean by "is actually safe" ? In the "can you actually
believe this obviously wrong code is marked as safe" or "this code
that looks wrong is actually perfectly safe"?
It's safe because of the implementation of arrays. There is always one
sentinel byte that cannot be used for the block of data. This is why
when you allocate e.g. 8 ints, it goes into a 32-byte block.
I take it back, it could be unsafe. You could have e.g. a 12 byte struct
be T, and then the last "element" could extend through the end of the
block.
A possible fix could be to reject the call to ptr at runtime if the slice
is empty.
-Steve
