title: what will happen for vuejs projects based on class components in vuejs v3.0?
body: <p>I wanna upgrade my vuejs project to typescript based on class components, but i read in vue issue's <a href="https://github.com/vuejs/rfcs/pull/17#issuecomment-494242121" rel="noreferrer">https://github.com/vuejs/rfcs/pull/17#issuecomment-494242121</a> :</p>
  <blockquote>
  <p>Update: the Class API proposal is being dropped.</p>
  </blockquote>
  <p>so what will happen to existing class component-based projects?
  and more important, based on this article:
  <a href="https://alligator.io/vuejs/using-typescript-with-vue/" rel="noreferrer">https://alligator.io/vuejs/using-typescript-with-vue/</a> which says</p>
  <blockquote>
  <p>Since we are not using the class-style syntax, you use the as keyword
  to declare data as a data type.</p>
  </blockquote>
  <p>is this way of using typescript safe in vue3.0?</p>