rust/src/test/run-pass/trait-inheritance-diamond.rs

35 lines
1.0 KiB
Rust

// 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.
// 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 S: A { fn a(&self) -> int { 10 } }
impl S: B { fn b(&self) -> int { 20 } }
impl S: C { fn c(&self) -> int { 30 } }
impl S: D { fn d(&self) -> int { 40 } }
fn f<T: D>(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);
}