Region#subst ICE with certain uses of 'self

[emberian]

Stripped-down and updated version of original source:

pub trait Interner<T> {
    fn new() -> Self;
    fn get(&'self self, tag: uint) -> Option<&'self T>;
}

pub struct SimpleInterner<T: Eq + IterBytes + Hash + Clone>;

impl<T> Interner<T> for SimpleInterner<T> {
    pub fn new() -> SimpleInterner<T> { SimpleInterner }
    pub fn get(&'self self, tag: uint) -> Option<&'self T> { None }
}

% rustc --version
/Users/fklock/opt/rust-dbg/bin/rustc 0.9-pre (97cd495 2013-10-02 01:16:31 -0700)
host: x86_64-apple-darwin
% rustc --lib /tmp/s.rs
error: internal compiler error: ty::Region#subst(): Reference to self region when given substs with no self region: substs(regions=[], self_ty=Some(BUG[1u]), tps=[T])

Original bug report: https://gist.github.com/pnkfelix/6905109

[erickt]

@dwrensha ran into a similar bug, but it's a bit shorter than the one you posted:

trait Constructable<'self> { fn construct(v : &'self[u8]) -> Self; }
fn main() { }

errored with:

error: internal compiler error: ty::Region#subst(): Reference to self region when given substs with no self region: substs(self_r=None, self_ty=Some(BUG[0]), tps=[])

[emberian]

"a bit shorter": understatement of the month!

[pnkfelix]

visiting for triage, email from 2013 sep 30.

Stripped bug down. Reviewing other bugs with 'self lifetime issues now to see how many dupes there are.

[nikomatsakis]

cc me

[nikomatsakis]

cc me

[luqmana]

The special 'self lifetime no longer exists and rewriting the code sample above to use some lifetime 'a doesn't trigger an ICE.

Tested with rustc 0.10-pre (6e7f170 2014-03-03 05:51:38 -0800)