gtk:window-mnemonic-modifier (window)

window -- a gtk:window widget
modifier -- a gdk:modifier-type value with the modifier mask used to activate mnemonics on window

Accessor of the modifier mask used to activate mnemonics on the window. The gtk:window-mnemonic-modifier function returns the mnemonic modifier for the window. The (setf gtk:window-mnemonic-modifier) function sets the mnemonic modifier.