[perl #131174] [NYI] Atrribute Introspect shape

[via RT]

# New Ticket Created by  David Warring 
# Please include the string:  [perl #131174]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org/Ticket/Display.html?id=131174 >


AFAIK there's currently no way of introspecting the shape of a Class
attribute that's a native shaped array.

I'd like this feature for the Native::Packing module. For example to
interpret:

class C {
    has byte @.gif-header[6];
    has uint16 $.width;
    has uint16 $height;
}

At the moment, I just can't determine the size of shaped native arrays,
such as @.gif-header above:

say .type, .container
    for C.^attributes;

(Positional[byte])(array[byte])
(uint16)(uint16)
(uint16)(uint16)