require 'benchmark'

arr = [*0..99999]
num = 100
Benchmark.bmbm do |x|
  x.report("sym#to_proc") do
    num.times do
      arr.each(&:to_i)
    end
  end

  x.report("traditional block") do
    num.times do
      arr.each {|i| i.to_i}
    end
  end
end

# For: arr = [*0..99999] and num = 100
# Rehearsal -----------------------------------------------------
# sym#to_proc         3.130000   0.010000   3.140000 (  3.137098)
# traditional block   1.470000   0.000000   1.470000 (  1.477588)
# -------------------------------------------- total: 4.610000sec
#
#                         user     system      total        real
# sym#to_proc         3.060000   0.010000   3.070000 (  3.069627)
# traditional block   1.470000   0.000000   1.470000 (  1.475297)