PGUMA

<h2 id="what's-new">
<a class="header-anchor-link" href="#what's-new" aria-hidden="true"></a> what's new</h2>
<p><span class="embed-block zenn-embedded zenn-embedded-card"><iframe id="zenn-embedded__2811c4920f1af" src="https://embed.zenn.studio/card#zenn-embedded__2811c4920f1af" data-content="https%3A%2F%2Fkotlinlang.org%2Fdocs%2Fwhatsnew15.html" frameborder="0" scrolling="no" loading="lazy"></iframe></span><a href="https://kotlinlang.org/docs/whatsnew15.html" style="display:none" target="_blank" rel="nofollow noopener noreferrer">https://kotlinlang.org/docs/whatsnew15.html</a></p>


<h2 id="sealed-interfaces">
<a class="header-anchor-link" href="#sealed-interfaces" aria-hidden="true"></a> Sealed interfaces</h2>
<p>実装先のクラスを網羅していないとwhen式の中でコンパイルエラーにできるようになった</p>


<h2 id="package-wide-sealed-class-hierarchies">
<a class="header-anchor-link" href="#package-wide-sealed-class-hierarchies" aria-hidden="true"></a> Package-wide sealed class hierarchies</h2>
<p>Sealedクラスの定義可能な範囲が同一ファイル内から同一パッケージに広がったって感じ？</p>
