destructure.rb

require 'benchmark/ips'

Benchmark.ips do |x|
  RESULT = [1]

  x.report('first') do |times|
    i = 0
    while i < times
      id = RESULT.first
      i += 1
    end
  end

  x.report('index') do |times|
    i = 0
    while i < times
      id = RESULT[0]
      i += 1
    end
  end

  x.report('at') do |times|
    i = 0
    while i < times
      id = RESULT.at(0)
      i += 1
    end
  end

  x.report('multiple assignment') do |times|
    i = 0
    while i < times
      id, _ = RESULT
      i += 1
    end
  end
end

results

ruby 1.9.3p327 (2012-11-10 revision 37606) [x86_64-darwin11.4.2]

Calculating -------------------------------------
               first     47576 i/100ms
               index     58701 i/100ms
                  at     63381 i/100ms
 multiple assignment     47781 i/100ms
-------------------------------------------------
               first 13747991.6 (±4.9%) i/s -   68366712 in   4.991485s
               index 22703483.4 (±7.6%) i/s -  112060209 in   4.989942s
                  at 12546992.2 (±2.6%) i/s -   62620428 in   4.995312s
 multiple assignment 22409002.3 (±3.6%) i/s -  111568635 in   4.987226s


jruby 1.7.0 (1.9.3p203) 2012-10-22 ff1ebbe on Java HotSpot(TM) 64-Bit Server VM 1.6.0_43-b01-447-11M4203 [darwin-x86_64]

Calculating -------------------------------------
               first     48796 i/100ms
               index     58585 i/100ms
                  at     80813 i/100ms
 multiple assignment     80660 i/100ms
-------------------------------------------------
               first 28412958.4 (±39.0%) i/s -  122380368 in   4.954999s
               index 25402739.2 (±23.4%) i/s -  114650845 in   4.964001s
                  at 24100236.8 (±16.7%) i/s -  115643403 in   4.973001s
 multiple assignment 32687016.2 (±24.8%) i/s -  150672880 in   4.960000s


MacRuby 0.11 (ruby 1.9.2) [universal-darwin10.0, x86_64]

Calculating -------------------------------------
               first     68024 i/100ms
               index     71208 i/100ms
                  at     68211 i/100ms
 multiple assignment     69491 i/100ms
-------------------------------------------------
               first 14137655.2 (±2.5%) i/s -   70608912 in   4.997973s
               index 37691986.6 (±5.3%) i/s -  186992208 in   4.993058s
                  at 12826278.0 (±6.1%) i/s -   63777285 in   4.998677s
 multiple assignment 18764141.7 (±16.3%) i/s -   84779020 in   5.018970s

rubinius 2.0.0.rc1 (1.8.7 f915f7e4 yyyy-mm-dd JI) [x86_64-apple-darwin12.2.0]

Calculating -------------------------------------
               first    175348 i/100ms
               index    199008 i/100ms
                  at    227895 i/100ms
 multiple assignment    225671 i/100ms
-------------------------------------------------
               first 45533567.5 (±0.8%) i/s -  227601704 in   4.998850s
               index 17716844.7 (±1.1%) i/s -   88558560 in   4.999225s
                  at 66112795.4 (±1.6%) i/s -  330447750 in   4.999731s
 multiple assignment 20989946.5 (±1.0%) i/s -  104937015 in   4.999864s