Tinkering with Nim OOP - what's wrong?

OOP Test is wrong

type
    A = ref A_obj

    A_obj = object {.inheritable}
        forward_deps: seq[A]


    B[T] = ref B_obj[T]

    B_obj[T] = object of A_obj
        values: seq[T]


proc new_B–ish[T](): T =
    new result
    result.values = @[]
    result.forward_deps = @[]


# May be added at a later time
type
    C_obj[T] = object of B_obj[T]
    C[T] = ref C_obj[T]

proc new_C[T](): C[T] =
    result = new_B–ish[C[T]]()
    # Does other things too...

# May be added at a later time
type
    D[T1, T2] = ref object of B_obj[T1]
        s1:         ptr T1
        s2:         ptr T2

proc `*`[T1, T2](in_s1: B[T1], in_s2: B[T2]): D[T1, T2] =
    result = new_B–ish[D[T1, T2]]
    # other stuff happens here...

method do_process[T1, T2](o: D[T1, T2]) =
    while true:
        # Does stuff...
        break

# Test instantiation
var c_thing = new_C[float64]()
var other_thing = c_thing * c_thing