is_null_xptr	is_null_xptr
is_xptr	is_xptr
new_xptr	new_xptr
null_xptr	new_xptr
register_xptr_finalizer	register_xptr_finalizer
set_xptr_address	set_xptr_address
set_xptr_protected	set_xptr_protected
set_xptr_tag	set_xptr_tag
xptr	xptr
xptr_address	xptr_address
xptr_clear	xptr_clear
xptr_protected	xptr_protected
xptr_tag	xptr_tag
