Difference between dstring and string format specifiers support. Bug?

[Ali Çehreli via Digitalmars-d-learn]

On 11/09/2016 01:20 AM, Ali Çehreli wrote:

 > arrayPtrDiff() is at the bottom of the same file but works correctly
 > only for char strings:
 >
 >   https://github.com/dlang/phobos/blob/master/std/format.d#L6573

What I meant is, using arrayPtrDiff() is correct only for char strings. 
Otherwise, arrayPtrDiff() is working properly.

Ali