title: What's the cleanest way of applying map() to a dictionary in Swift?
body: <p>I'd like to map a function on all keys in the dictionary. I was hoping something like the following would work, but filter cannot be applied to dictionary directly. What's the cleanest way of achieving this?</p>
  
  <p>In this example, I'm trying to increment each value by 1. However this is incidental for the example - the main purpose is to figure out how to apply map() to a dictionary.</p>
  
  <pre><code>var d = ["foo" : 1, "bar" : 2]
  
  d.map() {
      $0.1 += 1
  }
  </code></pre>