class Object
  include ::Lucky::QuickDef
  include ::Lucky::Memoizable

  def blank? : Bool
    if self.responds_to?(:empty?)
      self.empty?
    else
      false
    end
  end

  def present? : Bool
    !blank?
  end
end

struct Char
  def blank? : Bool
    case ord
    when 9, 0xa, 0xb, 0xc, 0xd, 0x20, 0x85, 0xa0, 0x1680, 0x180e,
         0x2000, 0x2001, 0x2002, 0x2003, 0x2004, 0x2005, 0x2006,
         0x2007, 0x2008, 0x2009, 0x200a, 0x2028, 0x2029, 0x202f,
         0x205f, 0x3000
      true
    else
      false
    end
  end
end

struct Nil
  def blank? : Bool
    true
  end
end