Benchmark to_proc vs block in Enumerable#map

benchmark.rb

#/usr/bin/env ruby

require "benchmark/ips"

arr = [1.0, 2.0, 3.0]

h = { foo: 1, bar: 2, baz: 3 }

class Double
  def to_proc
    proc{ |n| n * 2 }
  end
end

Benchmark.ips do |x|
  x.report("arr.map{ |x| x*2 }"){
    arr.map{ |x| x*2 }
  }

  x.report("arr.map(&Double.new)"){
    arr.map(&Double.new)
  }

  x.report("[:foo, :bar].map"){
    [:foo, :bar].map{ |x| h[x] }
  }

  x.report("[:foo, :bar].map(&h)"){
    [:foo, :bar].map(&h)
  }

  x.compare!
end