how to declare an immutable class?

[Jonathan M Davis via Digitalmars-d-learn]

On Thursday, August 11, 2016 21:49:46 Charles Hixson via Digitalmars-d-learn 
wrote:
> It works, it's just not the syntax that I'd prefer.  And it leaves me
> wondering exactly what
> immutable class Msg {...}
> was declaring.

All it does is make the members of the class immutable. It doesn't affect
the class itself - just like you could do

@safe class Msg {...}

and that has no effect on the class itself - just its members. I guess that
it's somewhat confusing given that some attributes affect the class itself
(e.g. public or abstract), but most don't, and if they don't, they just
affect the members of the class. But the type qualifiers - const, immutable,
and shared - do not affect the class itself, just its members. Off the top
of my head, I think that the only attributes that affect the actual class
are public, protected, package, private, static, abstract, and final - and
static doesn't even affect the class in all cases (e.g. it would have no
affect at the top-level of a module).

- Jonathan M Davis