Difference between dstring and string format specifiers support. Bug?

[Ali Çehreli via Digitalmars-d-learn]

On 11/09/2016 12:21 AM, Vadim Lopatin wrote:
> Looks like bug.
> dchar[] and wchar[] format strings support less specifiers than char[]
>
>         import std.format;
>         string test1 = "%02d".format(1); // works
>         assert(test1 == "01");
>         dstring test2 = "%d"d.format(1); // works
>         assert(test2 == "1"d);
>         wstring test3 = "%02d"w.format(1); // fails
>         assert(test3 == "01"w);
>         dstring test4 = "%02d"d.format(1); // fails
>         assert(test4 == "01"d);
>

It's a bug that std.format uses arrayPtrDiff() here:

   https://github.com/dlang/phobos/blob/master/std/format.d#L993

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

Please report it.

Ali