title: PromiseKit and CloudKit saving (using Swift)
body: <p>I'm new to PromiseKit and I'm a bit confused to how to handle multiple promises. I'm using CloudKit and saving two records, and when they are both saved, I want to do something on completion and something else on error. I thought I should do the following, but Xcode is complaining so obviously I must have misunderstood:</p>
  
  <pre><code>let savePromise1 : PMKPromise = db.saveRecord(record1)
  let savePromise2 : PMKPromise = db.saveRecord(record2)
  
  PMKPromise.when([ savePromise1, savePromise2 ]).then() { results in
      // handle success or errors
  }
  </code></pre>
  
  <p>The error I get is "Cannot convert the experssion's type '(($T8) -> ($T8) -> $T7) -> (($T8) -> ($T7) -> $T7' to type 'PMKPromise'</p>
  
  <p>I don't really understand what the error means, but I was expecting "results" to be an array of (result, error) tuples.</p>
  
  <p>How should I write my "when" statement instead?</p>
  
  <p>Cheers</p>
  
  <p>Nik</p>