title: What does the (unary) * operator do in this Ruby code?
body: <p>Given the Ruby code </p>
  
  <pre><code>line = "first_name=mickey;last_name=mouse;country=usa" 
  record = Hash[*line.split(/=|;/)] 
  </code></pre>
  
  <p>I understand everything in the second line apart from the  <code>*</code> operator - what is it doing and where is the documentation for this? (as you might guess, searching for this case is proving hard...)</p>