scala map / type instantiation

can someone explain the best way to get around the following,
rather curious type error. Suppose I create a list of tuples like so:

scala> val ys = List((1,2), (3,4), (5,6))
 ys: List[(Int, Int)] = List((1,2), (3,4), (5,6))
 

Now, if I want to map this to a List(Int)

scala> ys.map((a: Int, b: Int) => a + b)
 <console>:9: error: type mismatch;
 found   : (Int, Int) => Int
 required: ((Int, Int)) => ?
    ys.map((a: Int, b: Int) => a + b)
                            ^
 

Any clues? I know I can use the for comprehension

scala> for ((a, b) <- ys) yield a + b
 res1: List[Int] = List(3, 7, 11)
 

But it feels wrong to bust out a comprehension in this setting. Thanks!

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