メモ

class Method
  def where
    to_s =~ /#<Method: ([\w:]+)(\(([\w:]+)\))?#/
    if $3
      name = $3
    else
      name = $1
    end
    name.split("::").inject(Object){|o,s|o.const_get(s)}
  end
end

module Foo
module Rubymod
  def m
  end
end
end

module Bar
class Rubyco
  include Foo::Rubymod
  def c
  end
end
end

r = Bar::Rubyco.new
p r.method(:m).where      #=> Foo::Rubymod
p r.method(:c).where      #=> Bar::Rubyco