README.md

Benchmarking #map

#map(&:id) is faster than a block.
#map is faster than #each_with_object when doing roughly the same work.

In short, this might make you want to extract more public methods, even if you use them in decorators or proxy objects, that you can call with Symbol#to_proc.

benchmark.rb

require 'benchmark/ips'

User = Struct.new(:id)
a = Array.new(1000) { |i| User.new(i) }

Benchmark.ips do |x|
  x.report('#each_with_object') do
    a.each_with_object([]) do |i, a|
      a << i.id
    end
  end

  x.report('#map') do
    a.map do |i|
      i.id
    end
  end

  x.report('#map(&:id)') do
    a.map(&:id)
  end
end

results.txt

Calculating -------------------------------------
   #each_with_object   775.000  i/100ms
                #map     1.381k i/100ms
          #map(&:id)     1.851k i/100ms
-------------------------------------------------
   #each_with_object      8.082k (± 3.6%) i/s -     41.075k
                #map     14.547k (± 3.5%) i/s -     73.193k
          #map(&:id)     19.841k (± 3.5%) i/s -     99.954k