sizeof expression returns an
Int32 with the size in bytes of a given type. For example:
sizeof(Int32) # => 4 sizeof(Int64) # => 8
For Reference types, the size is the same as the size of a pointer:
# On a 64 bits machine sizeof(Pointer(Int32)) # => 8 sizeof(String) # => 8
This is because a Reference's memory is allocated on the heap and a pointer to it is passed around. To get the effective size of a class, use instance_sizeof.
a = 1 sizeof(typeof(a)) # => 4