type
  # An object which will be allocated on stack
  Animal = object
    name: string
    legs: int

# Non ref objects (stack objects) cannot be mutated
# inside methods
proc setName(a: Animal, name: string) =
  a.name = name

var dog = Animal(name: "shadow", legs: 4)
dog.name = "lucy"
dog.setName("jimmy")
# Object types can be converted to string with $
echo $dog