Speed of delegation in ruby

benchmark.rb

require "active_support/core_ext/module"
require 'benchmark'

class Test
  def initialize
    @time = Time.now
  end

  delegate :to_i, to: :@time, prefix: :ar

  def two
    @time.to_i
  end

  define_method :three do
    @time.to_i
  end

  class_eval <<CHUNK
  def #{"four"}
    @#{"time"}.to_i
  end
CHUNK
end

instance = Test.new
iterations = 10_000_000
Benchmark.bm(10) do |bm|
  bm.report("delegated") { iterations.times { instance.ar_to_i    } }
  bm.report("defined")   { iterations.times { instance.two        } }
  bm.report("def_meth")  { iterations.times { instance.three      } }
  bm.report("eval")      { iterations.times { instance.four       } }
end

#                  user     system      total        real
# delegated    2.770000   0.010000   2.780000 (  2.806770)
# defined      1.950000   0.010000   1.960000 (  1.966655)
# def_meth     2.450000   0.020000   2.470000 (  2.516374)
# eval         1.890000   0.000000   1.890000 (  1.900834)