title: How do I make method param mutable in Kotlin?
body: <p>I'm implementing a <code>SpinnerAdapter</code> in Android project. So I have to override <code>getView(i: Int, convertView: View, parent: ViewGroup)</code> method. So <code>convertView</code> is here in order to reuse existing view and reduce memory usage and GC occurrences. So if it is <code>null</code> I have to create view and use already created otherwise. </p>
  
  <p>So in fact I have to write something like this (officially recomended by google):</p>
  
  <pre><code>if (view == null) {
      view = View.inflate(context, R.layout.item_spinner, parent)
      view.tag(Holder(view))
  } else {
      (view.tag as Holder).title.text = getItem(i)
  }
  </code></pre>
  
  <p>But Kotlin does not allow to write to param.
  What I found on the internet is an official <a href="https://blog.jetbrains.com/kotlin/2013/02/kotlin-m5-1/" rel="noreferrer">blog post</a> that says that it is not possible since Feb, 2013. </p>
  
  <p>So I'm wondering if there is any workaround ?</p>