#![feature(specialization)] // Common code used for tests that model the Fn/FnMut/FnOnce hierarchy. pub trait Go { fn go(&self, arg: isize); } pub fn go(this: &G, arg: isize) { this.go(arg) } pub trait GoMut { fn go_mut(&mut self, arg: isize); } pub fn go_mut(this: &mut G, arg: isize) { this.go_mut(arg) } pub trait GoOnce { fn go_once(self, arg: isize); } pub fn go_once(this: G, arg: isize) { this.go_once(arg) } impl GoMut for G where G : Go { default fn go_mut(&mut self, arg: isize) { go(&*self, arg) } } impl GoOnce for G where G : GoMut { default fn go_once(mut self, arg: isize) { go_mut(&mut self, arg) } }