Menu class/struct for RPG
defualt_title and defualt_options are misspelled.
Those empty else{;} statements are unnecessary.  If there is eventually a need for actual else statements, then they can be added later.
With those "stray" data members, this should really be a class so that they can be private.  Data members should not be directly exposed to the interface.  Any functions that shouldn't be called by the user should also be private, otherwise they should be public.