module ClassProp::MustDefine

This module itself does not do anything. If you set a class property to ClassProp::MustDefine then subclasses must define that property. For example, the following code raise an exception.

class Base
    include ClassProp
    define_class_prop 'independent'
    self.independent = ClassProp::MustDefine
end

class X1 < Base
end

X1.independent # raises exception 'must-define-class-property: independent'