// Copyright 2014-2018 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution.
//
// 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.

use std::fmt;
use std::marker::PhantomData;

pub struct Key<T> {
    #[doc(hidden)]
    pub __name: &'static str,
    #[doc(hidden)]
    pub __phantom: PhantomData<T>,
}

impl<T> Copy for Key<T> {}

impl<T> Clone for Key<T> {
    fn clone(&self) -> Self {
        Key {
            __name: self.__name,
            __phantom: self.__phantom,
        }
    }
}

fn main() {}