gobject:value-flags (gvalue)

gvalue -- a g:value instance whose type is derived from "GFlags"
value -- a list with keywords or an unsigned integer with the flags value

Flags contents of gvalue. The g:value-flags function gets the contents of a g:value instance of type "GFlags". The (setf g:value-flags) function sets the contents.

(gobject:with-value (gvalue "GApplicationFlags")
  (setf (g:value-flags gvalue) '(:handles-open :is-service))
  (g:value-flags gvalue))
=> (:IS-SERVICE :HANDLES-OPEN)