openwat.rb

require 'benchmark/ips'
require 'ostruct'

struct = Struct.new(:name)

Benchmark.ips do |bench|
  bench.report 'Struct' do
    struct.new(:name => 'Alice')
  end

  bench.report 'Struct inline' do
    Struct.new(:name).new(:name => 'Alice')
  end

  bench.report 'OpenStruct' do
    OpenStruct.new(:name => 'Alice')
  end

  bench.compare!
end

output

Calculating -------------------------------------
              Struct    69.264k i/100ms
       Struct inline     8.916k i/100ms
          OpenStruct    11.488k i/100ms
-------------------------------------------------
              Struct      1.300M (± 3.2%) i/s -      6.511M
       Struct inline     89.434k (±13.2%) i/s -    445.800k
          OpenStruct    133.604k (± 6.1%) i/s -    666.304k

Comparison:
              Struct:  1299835.3 i/s
          OpenStruct:   133604.2 i/s - 9.73x slower
       Struct inline:    89434.1 i/s - 14.53x slower