type ctxt = { v: uint }; iface get_ctxt { fn get_ctxt() -> &self.ctxt; } type has_ctxt = { c: &ctxt }; impl of get_ctxt for has_ctxt { fn get_ctxt() -> &self.ctxt { self.c } } fn make_gc() -> get_ctxt { let ctxt = { v: 22u }; let hc = { c: &ctxt }; ret hc as get_ctxt; //~ ERROR mismatched types: expected `get_ctxt/&` } fn main() { make_gc().get_ctxt().v; }