src/test/ui/issues/issue-2063-resource.rs

// check-pass
#![allow(dead_code)]
// test that autoderef of a type like this does not
// cause compiler to loop.  Note that no instances
// of such a type could ever be constructed.

struct S {
  x: X,
  to_str: (),
}

struct X(Box<S>);

fn main() {}