* yes, to make inheritance easier (vars of different types (ancestors, descendants) are of the same size, size of a pointer) * no copying when passing - good for large objects, or when transmitted or used as arguments often * you can use arrays/seqs of different-sized (disregarding inheritance) ref-objects - really arrays of pointers * you can even store them in collections of arbitrary references (of any, incl. non-object, type) or just pointer-sized values
And the like, just examples. Ref-objects are allocated on heap, that is they require memory allocation, so when you don't have reasons to use them (in simple cases esp.), better to use value objects, which in Nim are no-overhead (say, a no-inheritance object containing 2 integers is of the size 2 integers, which are located directly in it and are passed to procs on stack).
