benchmark.rb

require 'benchmark'
 
n = 100000
Benchmark.bm do |x|
   x.report('copy') { n.times do ; h = {}; h = h.merge({1 => 2}); end }
   x.report('no copy') { n.times do ; h = {}; h.merge!({1 => 2}); end }
   x.report('aha') { n.times do; puts 'your shit here'; end }
end