title: Could vue3 <script setup> use component is, how to make it work?
body: <p>I am new beginner of vue3 and found that vue have three way to write component:</p>
  <ul>
  <li>&lt;script setup&gt;</li>
  <li>normal-setup/composition api</li>
  <li>options api.</li>
  </ul>
  <p>I know how to use  in normal composition api like this:</p>
  <pre><code>&lt;script&gt;
  import CommonLayout from &quot;@/components/Layout/CommonLayout.vue&quot;;
  export default {
    components: {
      CommonLayout,
    },
    setup() {
      const layout = &quot;CommonLayout&quot;;
      return { layout };
    },
  };
  &lt;/script&gt;
  &lt;template&gt;
    &lt;div&gt;
      {{ layout }}
      &lt;component :is=&quot;layout&quot;&gt;123&lt;/component&gt;
    &lt;/div&gt;
  &lt;/template&gt;
  </code></pre>
  <p>it really works.</p>
  <p>but I try to use setup script, it failed:</p>
  <pre><code>
  &lt;script setup&gt;
  import CommonLayout from &quot;@/components/Layout/CommonLayout.vue&quot;;
  const layout = &quot;CommonLayout&quot;;
  &lt;/script&gt;
  &lt;template&gt;
    &lt;div&gt;
      {{ layout }}
      &lt;component :is=&quot;layout&quot;&gt;123&lt;/component&gt;
    &lt;/div&gt;
  &lt;/template&gt;
  
  &lt;style&gt;&lt;/style&gt;
  
  </code></pre>