require 'benchmark/ips'

h = {:bar => 'uco'}

Benchmark.ips do |x|
  x.report('fetch with no block') { h.fetch(:bar, (0..9).to_a)    }
  x.report('fetch with a block')  { h.fetch(:bar) { (0..9).to_a } }
  x.report('brackets with an ||') { h[:bar] || (0..9).to_a        }
end