Struct That Disallows nil

struct_that_disallows_nil_values.rb

module StructThatDisallowsNil
  def self.new(*args)
    Struct.new(*args).tap do |klass|
      klass.prepend Module.new {
        def initialize(*)
          super
          members.each do |member|
            fail "#{member} cannot be nil" if send(member).nil?
          end
        end

        klass.members.each do |member|
          define_method("#{member}=") do |value|
            fail "#{member} cannot be nil" if value.nil?
            super
          end
        end
      }
    end
  end
end

YourClass = StructThatDisallowsNil.new(:foo, :bar, keyword_init: true)
YourClass.new(foo: 123, bar: 234) # works
YourClass.new(foo: nil, bar: 234) # fail

yc = YourClass.new(foo: 123, bar: 234)
yc.foo = nil # fail
yc.foo = 234 #works