swapping handles
I know that, under Symantec C++ with virtual methods, you're probably begging
for trouble doing this. More than likely you'll have trouble under THINK C,
also.
I'm not certain, but it's quite probable that the handle to an object points to
more than just the "data" (instance variables). There's probably also some
information to make virtual functions work correctly, and to make the member
function do its thing.
I would suggest using the standard TCL way of doing Undo, by using a task.
Joe