rust/src/test/compile-fail/issue-2611-4.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.

// Tests that an impl method's bounds aren't *more* restrictive
// than the trait method it's implementing

trait A {
  fn b<C,D>(&self, x: C) -> C;
}

struct E {
 f: isize
}

impl A for E {
    fn b<F: Sync, G>(&self, _x: F) -> F { panic!() }
    //~^ ERROR `F : std::marker::Sync` appears on the impl method
}

fn main() {}