What if x is an "optional" out parameter: EG: something you
only set if other conditions are met? Do you want to make sure
that x is at least assigned to once, or rather make it an error
to have a control path that *doesn't* assign anything to it.
Either way:
1. Making it an error to have a control path that doesn't
assign to x would be counter productive, as the result would
probably end up being code that looks like:
foo(out int x) {
x = 0;
...
}
which would defeat the entire point of out.
2. Checking the variable is at least used would be kind of the
same as checking for unused arguments. I think that'd be fine,
provided you could over-ride the warning by not naming your
variable:
foo(out int x){} //Error, x is never assigned to (or used)
foo(out int){} //OK!
Today a function with return value but without return statement
is already an error. Why not return ReturnType.init instead? It's
absolutely the same.
