Why do Scala Ints lack the postfix increment operator, but HashMaps don't?
scala
Solution
The `++` operator is not meant as an imperative increment operator, but as a union of two collection, such that it produces new collections instead of modifying either of the old ones.
Problem
Many data types in scala, like HashMaps, have the postfix increment operator implemented, but Ints and Doubles have not. Is it because if there was a postfix operator for numbers, there had to be a prefix operator too, and that would not fit the way operators are implemented in scala (as methods)?