ge-rust">fn main() {
    let x = 4;

    let equal_to_x = |z| z == x;

    let y = 4;

    assert!(equal_to_x(y));
}</code></pre></pre>
<!--
<span class="caption">Listing 13-12: Example of a closure that refers to a
variable in its enclosing scope</span>
-->
<p><span class="caption">リスト13-12: 内包するスコープの変数を参照するクロージャの例</span></p>
<!--
Here, even though `x` is not one of the parameters of `equal_to_x`, the
`equal_to_x` closure is allowed to use the `x` variabl