ICE: trait fn returning &'self => 'region parameterization should have inferred that this type is RP'

[ben0x539]

sample code:

trait Tr<'self> {
    fn f(&self) -> &'self int;
}

fn g<T: Tr<'self>>() {}

fn main() {}

rustc ICE:

rust: task failed at 'region parameterization should have inferred that this type is RP', [...]/rust/src/librustc/middle/typeck/rscope.rs:230

[metajack]

Still an ICE.

not sure if this is important, but nominating for discussing to production ready

[catamorphism]

Sub-bug of #4846, de-nominating

[ben0x539]

The example code doesn't compile anymore and I can't get it to throw that error anymore by fiddling with it, so I assume this was fixed at some point but I'm not sure what a regression test would look like. Do we need one?

[alexcrichton]

This fails with a legitimate error today, and I've seen relevant tests for this in the tests suite, so closing.