an>);
}

<span class='kw'>fn</span> <span class='ident'>double</span>(<span class='ident'>x</span>: <span class='ident'>i32</span>) <span class='op'>-&gt;</span> <span class='ident'>i32</span> {
    <span class='ident'>x</span> <span class='op'>*</span> <span class='number'>2</span>
}</pre>

<span class='rusttest'>fn main() {
    let a = true;

    let _y = change_truth(a);
    println!(&quot;{}&quot;, a);
}

fn change_truth(x: bool) -&gt; bool {
    !x
}
</span><pre class='rust rust-example-rendered'>
<spa