pass reference of primitive data types to functions in ruby -

by default ruby passes copy of primitive values , references object types. how pass references of primitive type variables (ex: integers, floating points) function?

ruby doesn't pass arguments reference:

def change(x)   x = 2  # assigns local variable 'x' end  = 1 change(a) #=> 1 

you pass mutable object instead, e.g. hash "containing" integer:

def change(h)   h[:x] = 2 end  h = {x: 1} change(h) h[:x] #=> 2