Privacy, stability etc. are not respected in imports with empty braces

[petrochenkov]

use std::rt::{};

should warn that std::rt is unstable, but it doesn't.

mod m {
    mod n {}
}

use m::n::{};

should be caught by privacy checker, but it isn't.

See #28364 (comment) for some details.

[petrochenkov]

In fact, almost no checks are performed on the prefix, even

use foo::bar::baz::{};
fn main() {}

compiles successfully.
I think, instead of trying to resolve the prefix we could just prohibit empty braces in imports - this construction is useless to the limit, it can't even be obtained as a result of macro expansion.

[alexispurslane]

instead of trying to resolve the prefix we could just prohibit empty braces in imports - this construction is useless to the limit

I agree whole heartedly.

[alexispurslane]

Should I try to make empty braces disallowed? But I think that would need an RFC or at least approval from someone else.

[nagisa]

Needs RFC. There’s at least a few things impl-wise to be considered here.