class Object
  def self.measure(method, category_name=nil)
    alias_method "#{method}_unmeasured", method
    define_method method do |*args|
      cat_name = if category_name.respond_to?(:call)
                   # If proc eval in current context and pass args
                   self.instance_exec args, &category_name
                 elsif category_name && category_name.respond_to?(:to_s)
                   # Stringify that thing you gave me
                   category_name.to_s
                 else
                   # Try to be smart
                   args.first.try(:to_s)
                 end

      ActiveSupport::Notifications.instrument(
        "#{self.class.name}.#{method.to_s}",
        :name => cat_name
      ) do
        send "#{method}_unmeasured", *args
      end
    end
  end
end