In Programmazione in Scala , c'è questa dichiarazione:
For instance an empty mutable map in its default representation of HashMap takes up about 80 bytes and about 16 more are added for each entry that’s added to it. An empty immutable Map is a single object that’s shared between all references, so referring to it essentially costs just a single pointer field.
Perché una mappa mutevole richiede più spazio?