# Class virtual Cf_gadget.next

    class virtual [['i, 'o]] next : object .. end

Use `inherit ['i, 'o] next` to derive a class that implements an intermediate state in a machine.

    method private virtual guard : ('i, 'o, unit) guard

The guard evaluated by this state of the machine.

    method next : 'a. ('i, 'o, 'a) t

Use `obj#next` to transition the state of the gadget by applying `Cf_state_gadget.guard` `self#guard`.