Negation of attributes (DIP 79)

[Kapps via Digitalmars-d]

>This in theory reduce some kind of bugs, when one forget to mark 
>method as virtual.

It doesn't reduce bugs, it introduces noticeable bugs and 
slightly lowers performance. All at the benefit of not having to 
write' virtual'.

/pedantic

As for the actual DIP, I don't like final(false). It's simply far 
too verbose, and a double negative (not not overridable), same 
for @nogc(false). I slightly prefer !final (though it's again a 
double negative, but at least it's more consistent with bools and 
not function invocation), but even then it's not a nice solution. 
  Only decent one I can think of though, short of adding virtual.