def validates_primitive_type_of(*attribute_names)
      options = Macros.extract_options(attribute_names)
      validation_rules.add(Rule::PrimitiveType, attribute_names, options)
    end
def validates_primitive_type_of(*attribute_names)
      options = Macros.extract_options(attribute_names)
      validation_rules.add(Rule::PrimitiveType, attribute_names, options)
    end
Validates that the specified attribute is of the correct primitive
 type.

 @example Usage
   require 'virtus'
   require 'aequitas'

   class Person
     include Virtus
     include Aequitas

     attribute :birth_date, Date

     validates_primitive_type_of :birth_date

     # a call to valid? will return false unless
     # the birth_date is something that can be properly
     # casted into a Date object.
   end