Convert List of tuple to map (and deal with duplicate key ?)

For Googlers that don’t expect duplicates or are fine with the default duplicate handling policy:

List("a" -> 1, "b" -> 2, "a" -> 3).toMap
// Result: Map(a -> 3, c -> 2)

As of 2.12, the default policy reads:

Duplicate keys will be overwritten by later keys: if this is an unordered collection, which key is in the resulting map is undefined.