About structs and performant handling

[Namespace]

> You never gave any rationale reason on that.

Because I just like to have the control over what is passed by 
ref and what by value.
Maybe I want that a bigger struct is passed by value.
As long as I must denote parameters accordingly, in order that 
the compiler decide instead of me, this is no problem.
But if you have no control, because the compiler will decide for 
you, it would not be possible.
I'm considering a small example until evening.