Damian Conway wrote:
>  So, to clarify again, if $var is undefined, then the assignment:
>  
>      $var op= $value;
>  
>  is equivalent to:
>  
>      $var = (&op.does(identval) ?? &op.identval() :: undef) op $value;
>  
>  Correct?

Might I add that it should read

       $var = (&op.does(identval) ??
               &op.identval($value) :: undef) op $value;

The rational is, that &op is subject to MMD, so the .identval method
should be dispatched as well. Actually &op.identity($value) reads
quite natural and self documenting if the parameter is required.

Hmm, the MMD form identity( &op, $value ) looks even better. This
folds the identity value selection problem back into type-space
and it's runtime agent MMD.
-- 
TSa (Thomas Sandlaß)