Scala: How to create a Map[K,V] from a Set[K] and a function from K to V?

Question

What is the best way to create a Map[K,V] from a Set[K] and function from K to V?

For example, suppose I have

Answer 1

The other solutions lack creativity. Here's my own version, though I'd really like to get rid of the _.head map.

s groupBy identity mapValues (_.head) mapValues func