rust/src/test/compile-fail/coherence-impl-trait-for-trait.rs
Niko Matsakis 92d16d961d Fallout in tests -- break the object safety part into a separate file because error
will be in future reported by wfcheck, which runs in a later stage than
coherence
2015-08-12 17:58:56 -04:00

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939 B
Rust

// Copyright 2015 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.
// Test that we give suitable error messages when the user attempts to
// impl a trait `Trait` for its own object type.
trait Foo { fn dummy(&self) { } }
trait Bar: Foo { }
trait Baz: Bar { }
// Supertraits of Baz are not legal:
impl Foo for Baz { } //~ ERROR E0371
impl Bar for Baz { } //~ ERROR E0371
impl Baz for Baz { } //~ ERROR E0371
// But other random traits are:
trait Other { }
impl Other for Baz { } // OK, Other not a supertrait of Baz
fn main() { }