method_benchmarker.rb

module MethodBenchmarker
  def benchmarks(*methods)
    methods.flatten.each do |method|
      define_method("#{method}_with_benchmark") do |*args|
        r = nil
        secs = Benchmark.realtime { r = send("#{method}_without_benchmark", *args) }
        puts *[
          "\n##################################################",
          "Method '#{method}' took #{sprintf("%.4f", secs)} seconds",
          "##################################################"
        ]
        r
      end
      alias_method_chain method, :benchmark
    end
  end
end

# Example:
# 
# class X
#   extend MethodBenchmarker
#   
#   def foo
#   end
#
#   def bar
#   end
#   
#   benchmarks :foo, :bar
# end