Re: Is "is" the same as ptr == ptr for arrays?

[simendsjo]

On 07.08.2010 18:04, Peter Alexander wrote:

On 7/08/10 4:33 PM, simendsjo wrote:

Is the following equalent?

int[] a;
int[] b = a;
assert(a is b);
assert(a.ptr == b.ptr);

No.

(a is b) implies (a.ptr == b.ptr)

but

(a.ptr == b.ptr) does not imply (a is b)

For example:

int[] a = [1, 2, 3];
int[] b = a[0..1];

Here, a.ptr == b.ptr, but a !is b.

The ptr property returns a pointer to the first element, which is true
in this case, but it doesn't mean that they both refer to the same range.

Ok, thanks. Does this mean this equivalent then?

int[] a = [1,2,3];
int[] b = a[0..1];
assert(a !is b);
assert(a.ptr == b.ptr && a.length == b.length);