If the reference is NULL then this function does nothing.
Otherwise, the variable is destroyed using destroy and the
pointer is set to NULL.
A macro is also included that allows this function to be used without
pointer casts. This will mask any warnings about incompatible function types
or calling conventions, so you must ensure that your destroy function is
compatible with being called as GDestroyNotify using the standard calling
convention for the platform that GLib was compiled for; otherwise the program
will experience undefined behaviour.
Clears a reference to a variable.
pp must not be NULL.
If the reference is NULL then this function does nothing. Otherwise, the variable is destroyed using destroy and the pointer is set to NULL.
A macro is also included that allows this function to be used without pointer casts. This will mask any warnings about incompatible function types or calling conventions, so you must ensure that your destroy function is compatible with being called as GDestroyNotify using the standard calling convention for the platform that GLib was compiled for; otherwise the program will experience undefined behaviour.