gistfile1.ru

require 'benchmark'

Benchmark.bmbm do |x|
  x.report 'each_with_index' do
    i = []
    [*1..1000].each_with_index do |item, index|
      i << item*index
    end
  end
  
  x.report 'enum_for collect with_index' do
    [*1..1000].enum_for(:collect).with_index do |item,index|
      item*index
    end
  end
end