replace_qdata
Description:
[ Version ( since = "2.34" ) ]
public bool replace_qdata<G,T> (Quark quark, G oldval, owned T newval, out DestroyNotify? old_destroy)
Compares the user data for the key quark 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 |
| quark |
a Quark, 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 |