replace

Description:

public static bool replace (ref Object? oldobj, Object? newobj)

Atomically modifies a pointer to point to a new object.

The reference count of oldobj is decreased and the reference count of newobj is increased.

Either newobj and the value pointed to by oldobj may be null.

oldobj	pointer to a place of a Object to replace
newobj	a new Object

true if newobj was different from oldobj