What's the difference between -- and &~ in Scala

Question

'--' the document say: Creates a new $coll from this $coll by removing all elements of another collection.

'&~' the document say: The difference of this set and another set.

i use both of two symbol can get same result.

so is there have some difference between this two symbol? For example, there are different time complexity or memory occupation?

Answer 1

According to the Scaladoc .

-- accepts any kind of IterableOnce whereas &~ only accepts other Sets
Arguably, if you have two sets, you should prefer &~ since it is probably optimized.