ruby 1.8 + SimpleDelegator. extremly slow

delegate.rb

require 'delegate'
require 'benchmark'

class User
end

class UserPresenter < SimpleDelegator
end

N = 10_000

Benchmark.bmbm do |x|
  x.report("Without presenter") { N.times { User.new } }
  x.report("With presenter") { N.times { UserPresenter.new(User.new) } }
end

# Ruby 1.8
# Rehearsal -----------------------------------------------------
# Without presenter   0.010000   0.000000   0.010000 (  0.005536)
# With presenter      5.220000   0.000000   5.220000 (  5.287774)
# -------------------------------------------- total: 5.230000sec

#                         user     system      total        real
# Without presenter   0.010000   0.000000   0.010000 (  0.004076)
# With presenter      5.210000   0.010000   5.220000 (  5.283736)



# Ruby 1.9
# Rehearsal -----------------------------------------------------
# Without presenter   0.010000   0.000000   0.010000 (  0.005000)
# With presenter      0.010000   0.000000   0.010000 (  0.010731)
# -------------------------------------------- total: 0.020000sec
#                        user     system      total        real
# Without presenter   0.000000   0.000000   0.000000 (  0.003953)
# With presenter      0.010000   0.000000   0.010000 (  0.010640)