 {
    let n = test::black_box(1000);

    (0..n).fold(0, |a, b| a ^ b)
})
}
</span><pre class='rust rust-example-rendered'>
<span class='attribute'>#<span class='op'>!</span>[<span class='ident'>feature</span>(<span class='ident'>test</span>)]</span>

<span class='kw'>extern</span> <span class='kw'>crate</span> <span class='ident'>test</span>;

<span class='ident'>b</span>.<span class='ident'>iter</span>(<span class='op'>||</span> {
    <span class='kw'>let</span> <span class='ident'>n</span> <span class='