'typeof' question

[DLearner via Digitalmars-d-learn]

Trying to manipulate 'typeof' return strings, preferably at 
compile-time.

e.g. to produce struct B below (intended to have an A 
sub-struct), from A_Ptr alone.
```
struct A {
   int AFld1;
}
A* A_Ptr;
struct B {
   int BFld2;
   typeof(A_Ptr)[0..($-1)] ASUB; // Idea is ASUB of type A, from 
A_Ptr of type A*.
}
```
But this fails with 'can only slice tuple types...'.

Suggestions?