title: Assign to anonymous struct value in map
body: <p>I am using go 1.3.</p>
  
  <p>How can I access the fields of the anonymous struct ValueType of the map ? </p>
  
  <pre><code>package main
  
  import "fmt"
  
  type Words map[string]struct{
      pos   int
      n     int
  }
  
  func main() {
      w := make(Words)
      w["abc"].pos = 5 // cannot assign
  
      fmt.Println(w)
  }
  </code></pre>