use self instead of mod in import statements

[liigo]

After enum variants was name-spaced,
use Option::{mod, Some, None};
looks weird, because Option is NOT a module.
change mod to self would be more clear:
use Option::{self, Some, None};
use std::option::{self, Option};

[lifthrasiir]

Note that self also has a role of indicating a relative path so there is a possibility of confusion. Maybe an RFC material.

[tomjakubowski]

use Option::{enum, ..} is an alternative that seems more consistent with mod to me.

[liigo]

Normally self only appears at the front of a path, to indicate a relative path, maybe I'm wrong?
enum is good, too. self maybe better, for its generic.

[reem]

Just noting that this change would require an RFC.

[lifthrasiir]

I've written a simple RFC for this issue: rust-lang/rfcs#532.

[liigo]

closing in favor of RFC PR 532. thank you @lifthrasiir !