gistfile1.rb

class Proc
  def bind(receiver)
    unbound_method = receiver.class.unbound_method self
    unbound_method.bind receiver
  end
end

class Object
  def self.unbound_method(proc)
    define_method :__temp_unbound_method__, &proc
    x = instance_method(:__temp_unbound_method__)
    send :undef_method, :__temp_unbound_method__
    x
  end
end