// Copyright 2012 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 TraitA { fn method_a(&self) -> isize; } trait TraitB { fn gimme_an_a(&self, a: A) -> isize; } impl TraitB for isize { fn gimme_an_a(&self, a: A) -> isize { a.method_a() + *self } } fn call_it(b: B) -> isize { let y = 4us; b.gimme_an_a(y) //~ ERROR the trait `TraitA` is not implemented } fn main() { let x = 3; assert_eq!(call_it(x), 22); }