Cherry picking Modules

module.rb

module A
  def foo
    puts "A:foo"
  end
end

module B
  def foo
    puts "B:foo"
  end
end

module C
  def self.bar
    puts "C:bar"
  end
end

class Base
 include A
 include B
 include C

 def bar
  C.bar
 end

 def foo(module_name=A)
    module_name.instance_method(:foo).bind(self).call
 end

end

puts Base.new.is_a?(A)  # => true
puts Base.include?(A)   # => true

Base.new.foo(B)         # => B:foo
Base.new.foo(A)         # => A:foo
Base.new.foo            # => A:foo
Base.new.bar            # => C:bar