// Copyright 2016 The Rust Project Developers. See the COPYRIGHT // file at the top-level directory of this distribution and at // http://rust-lang.org/COPYRIGHT. // // Licensed under the Apache License, Version 2.0 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. trait Trait { fn foo(&self) -> Self; } fn call_foo(x: Box) { //~^ ERROR E0038 //~| NOTE the trait `Trait` cannot be made into an object //~| NOTE method `foo` references the `Self` type in its arguments or return type let y = x.foo(); } fn main() { }