Preventing implicit conversion

[ixid via Digitalmars-d-learn]

On Wednesday, 4 November 2015 at 14:27:49 UTC, ixid wrote:
> Is there an elegant way of avoiding implicit conversion to int 
> when you're using shorter types?

Also does this not seem inconsistent:

     ushort a = ushort.max, b = ushort.max;


     a += b; // Compiles fine
     a = a + b; // Error: cannot implicitly convert expression 
(cast(int)a + cast(int)b) of type int to ushort