You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: lib.rs
    path of file: ./repos/phaser/phaser/vendor/atty/src
    
    the code of the file until where you have to start completion: //! atty is a simple utility that answers one question
//! > is this a tty?
//!
//! usage is just as simple
//!
//! ```
//! if atty::is(atty::Stream::Stdout) {
//!   println!("i'm a tty")
//! }
//! ```
//!
//! ```
//! if atty::isnt(atty::Stream::Stdout) {
//!   println!("i'm not a tty")
//! }
//! ```

#![cfg_attr(unix, no_std)]

#[cfg(unix)]
extern 
    
pub fn is(stream: Stream) -> bool {
    use winapi::um::winbase::{
        STD_ERROR_HANDLE as STD_ERROR, STD_INPUT_HANDLE as STD_INPUT,
        STD_OUTPUT_HANDLE as STD_OUTPUT,
    };

    let (fd, others) = match stream {
        Stream::Stdin => (STD_INPUT, [STD_ERROR, STD_OUTPUT]),
        Stream::Stderr => (STD_ERROR, [STD_INPUT, STD_OUTPUT]),
        Stream::Stdout => (STD_OUTPUT, [STD_INPUT, STD_ERROR]),
    };
    if unsafe { console_on_any(&[fd]) } {
        // False positives aren't possible. If we got a console then
        // we definitely have a tty on stdin.
        return true;
    }

    // At this point, we *could* have a false negative. We can determine that
    // this is true negative if we can detect the presence of a console on
    // any of the other streams. If another stream has a console, then we know
    // we're in a Windows console and can therefore trust the negative.
    if unsafe { console_on_any(&others) } {
        return false;
    }

    // Otherwise, we fall back to a very strange msys hack to see if we can
    // sneakily detect the presence of a tty.
    unsafe { msys_tty_on(fd) }
}