rust/src/test/compile-fail/issue-2149.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 vec_monad<A> {
    fn bind<B, F>(&self, f: F) where F: FnMut(A) -> Vec<B>;
}

impl<A> vec_monad<A> for Vec<A> {
    fn bind<B, F>(&self, mut f: F) where F: FnMut(A) -> Vec<B> {
        let mut r = panic!();
        for elt in self.iter() { r = r + f(*elt); }
        //~^ ERROR the type of this value must be known
   }
}
fn main() {
    ["hi"].bind(|&mut: x| [x] );
    //~^ ERROR type `[&str; 1]` does not implement any method in scope named `bind`
}