�のドキュメントです。
  </p>
</blockquote>

    <h1 class="title">Lifetimes</h1>
    <p>Rust enforces these rules through <em>lifetimes</em>. Lifetimes are effectively
just names for scopes somewhere in the program. Each reference,
and anything that contains a reference, is tagged with a lifetime specifying
the scope it&#39;s valid for.</p>

<p>Within a function body, Rust generally doesn&#39;t let you explicitly name the
lifetimes involved. This is because it&#39;s generally not really necessary
