+(defun msgdi-device-p (&optional device)
+ "Return non-nil if DEVICE is a GDI device, that is 'mswindows or 'msprinter.
+MS GDI devices are mutuially WYSIWIG-compatible, so that many common glyph,
+color and font properties apply to them equally.
+
+This function is also a predicate for 'msgdi device tag, matching this
+device class."
+ (memq (device-type device) '(mswindows msprinter)))
+