Why is the `unary_` prefix needed in scala?

Question

Beginner Scala question, but I couldn\'t find the answer on here.

Similar to overloading in C++, I would expect the compiler can tell the difference between a method cal

Answer 1

Because in scala it is totally fine to create a method named -, that takes no arguments. How would you distinguish between a normal and a unary method? For example ! has a totally different meaning as unary, than as post fix operator.