Finally attr_accessor? & attr_reader? with question marks for booleans/predicates!? To get started, pick one: (1) in your class/module/file, add `using AttrBool::Ref`, or (2) in your class/module, add `extend AttrBool::Ext`, or (3) in your app/script (not library), include `require 'attr_bool/core_ext'`. Now simply use any: [ attr_accessor?, attr_reader?, attr_writer?, attr_bool, attr_bool?, attr_bool! ]. Keywords: attr, attribute, attributes, bool, boolean, booleans, predicate, predicates