pango:font-description-set-fields (desc)

desc -- a pango:font-description instance

The list for the pango:font-mask values set corresponding to the fields in desc that have been set.

Determines which fields in a font description have been set.

(pango:font-description-from-string "Sans Bold 16")
=> #<PANGO:FONT-DESCRIPTION {10077E5773}>
(pango:font-description-set-fields *)
=> (:FAMILY :STYLE :VARIANT :WEIGHT :STRETCH :SIZE)