rust/src/test/run-pass/trait-inheritance-multiple-params.rs

// 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 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

trait A { fn a(&self) -> int; }
trait B: A { fn b(&self) -> int; }
trait C: A { fn c(&self) -> int; }

struct S { bogus: () }

impl S: A { fn a(&self) -> int { 10 } }
impl S: B { fn b(&self) -> int { 20 } }
impl S: C { fn c(&self) -> int { 30 } }

// Multiple type params, multiple levels of inheritance
fn f<X: A, Y: B, Z: C>(x: &X, y: &Y, z: &Z) {
    assert x.a() == 10;
    assert y.a() == 10;
    assert y.b() == 20;
    assert z.a() == 10;
    assert z.c() == 30;
}

fn main() {
    let s = &S { bogus: () };
    f(s, s, s);
}