Define methods using templates

[Claude via Digitalmars-d-learn]

Thanks Steven and Daniel for your explanations.

>     mixin template opAssign(alias Field) {
>         void opAssign(Tin)(auto ref Tin param) @property pure 
> @safe
>         {
>             Field = param;
>             m_matrixCalculated = false;
>         }
>     }
>
>     mixin opAssign!(m_pos)   pos;

I tested both the "string mixin" and "opAssign" implementations, 
and they work like a charm.
I would have never thought of using both @property and 
"opAssign", but it looks like a secure way of doing it for the 
compilation fails nicely if I type a wrong field in.

src/camera.d(58): Error: undefined identifier m_os, did you mean 
variable m_pos?