+ (defclass font-extents (struct)
+ ((ascent :allocation :alien :reader font-extents-ascent :type double-float)
+ (descent :allocation :alien :reader font-extents-descent :type double-float)
+ (height :allocation :alien :reader font-extents-height :type double-float)
+ (max-x-advance :allocation :alien :reader font-extents-max-x-advance :type double-float)
+ (max-y-advance :allocation :alien :reader font-extents-max-y-advance :type double-float))
+ (:metaclass struct-class))