Tests whether a slot has been initialized.
Returns true if the slot in instance that would be accessed by the getter generic function is initialized. If the slot is not initialized, then false is returned.
slot-initialized? will signal an error if the getter does not access a slot in the instance.
To support slot-initialized? for a virtual slot, programmers must define a method for slot-initialized? that shares a protocol with the getter of the slot.
open
| instance | An instance of <object>. |
| getter | An instance of <generic-function>. |
| boolean | An instance of <boolean>. |