replace_data


Description:

[ Version ( since = "2.34" ) ]
public bool replace_data<G,T> (string key, G oldval, owned T newval, out DestroyNotify? old_destroy)

Compares the user data for the key key on this with oldval, and if they are the same, replaces oldval with newval.

This is like a typical atomic compare-and-exchange operation, for user data on an object.

If the previous value was replaced then ownership of the old value (oldval) is passed to the caller, including the registered destroy notify for it (passed out in old_destroy). It’s up to the caller to free this as needed, which may or may not include using old_destroy as sometimes replacement should not destroy the object in the normal way.

Parameters:

this

the Object to store user data on

key

a string, naming the user data pointer

oldval

the old value to compare against

newval

the new value

old_destroy

destroy notify for the existing value

destroy

a destroy notify for the new value

Returns:

true if the existing value for key was replaced by newval, false otherwise.