title: Using "if let" with logical "or" operator
body: <p>I'm trying to write the following block of code in a single <code>if let</code> line:</p>
  
  <pre><code> if let amount = datasource?.incrementForCount?(count) {
  
          count += amount
      }
  
      else if let amount = datasource?.fixedIncrement {
          count += amount
      }
  </code></pre>
  
  <p>when I try something like:</p>
  
  <pre><code> if let amount = datasource?.incrementForCount?(count) ||  let amount = datasource?.fixedIncrement {
  
          count += amount
      }
  </code></pre>
  
  <p>I got a compile time error.</p>
  
  <p>I don't think that <code>where</code> clause is possible for this case.</p>
  
  <p>Is it possible to combine the two <code>if let</code> statements into a single <code>ORed</code> one?</p>