rust/src/test/compile-fail/private-struct-field.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.

mod cat {
    pub struct Cat {
        meows: usize
    }

    pub fn new_cat() -> Cat {
        Cat { meows: 52 }
    }
}

fn main() {
    let nyan = cat::new_cat();
    assert_eq!(nyan.meows, 52);    //~ ERROR field `meows` of struct `cat::Cat` is private
}