type ctxt = { v: uint }; trait get_ctxt { fn get_ctxt() -> &self/ctxt; } type has_ctxt = { c: &ctxt }; impl has_ctxt: get_ctxt { fn get_ctxt() -> &self/ctxt { self.c } } fn get_v(gc: get_ctxt) -> uint { gc.get_ctxt().v } fn main() { let ctxt = { v: 22u }; let hc = { c: &ctxt }; // This no longer works, interestingly, due to the ownership // requirement. Perhaps this ownership requirement is too strict. // assert get_v(hc as get_ctxt) == 22u; }