// 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. // B and C both require A, so D does as well, twice, but that's just fine trait A { fn a(&self) -> int; } trait B: A { fn b(&self) -> int; } trait C: A { fn c(&self) -> int; } trait D: B + C { fn d(&self) -> int; } struct S { bogus: () } impl A for S { fn a(&self) -> int { 10 } } impl B for S { fn b(&self) -> int { 20 } } impl C for S { fn c(&self) -> int { 30 } } impl D for S { fn d(&self) -> int { 40 } } fn f(x: &T) { assert!(x.a() == 10); assert!(x.b() == 20); assert!(x.c() == 30); assert!(x.d() == 40); } pub fn main() { let value = &S { bogus: () }; f(value); }