Legal operator overloading

[Nicholas Wilson via Digitalmars-d-learn]

Is it legal/possible to overload the unary * operator? Also is it 
legal/possible to individually overload the comparison operators 
and not return a bool?

(Before you ask no I'm not crazy, I am trying to make a library 
solution to multiple address spaces for supporting OpenCL/CUDA in 
D, and vector comparisons.)