Ruby 2.4 has optimized enumerable min max methods

Enumerables in Ruby have min, max and minmax comparison methods which are quite convenient to use.

(1..99).min #=> 1
(1..99).max #=> 99
(1..99).minmax #=> [1, 99]

In Ruby 2.4, Enumurable#min, Enumurable#max methods and Enumurable#minmax method are now more optimized.

We would run the following benchmark snippet for both Ruby 2.3 and Ruby 2.4 and observe the results

require 'benchmark/ips'

Benchmark.ips do |bench|
NUM1 = 1_000_000.times.map { rand }

ENUM_MIN = Enumerable.instance_method(:min).bind(NUM1)
ENUM_MAX = Enumerable.instance_method(:max).bind(NUM1)
ENUM_MINMAX = Enumerable.instance_method(:minmax).bind(NUM1)

bench.report('Enumerable#min') do
ENUM_MIN.call
end

bench.report('Enumerable#max') do
ENUM_MAX.call
end

bench.report('Enumerable#minmax') do
ENUM_MINMAX.call
end
end

Results for Ruby 2.3

Warming up --------------------------------------
Enumerable#min 1.000 i/100ms
Enumerable#max 1.000 i/100ms
Enumerable#minmax 1.000 i/100ms
Calculating -------------------------------------
Enumerable#min 14.810 (±13.5%) i/s - 73.000 in 5.072666s
Enumerable#max 16.131 (± 6.2%) i/s - 81.000 in 5.052324s
Enumerable#minmax 11.758 (± 0.0%) i/s - 59.000 in 5.026007s

Ruby 2.4

Warming up --------------------------------------
Enumerable#min 1.000 i/100ms
Enumerable#max 1.000 i/100ms
Enumerable#minmax 1.000 i/100ms
Calculating -------------------------------------
Enumerable#min 18.091 (± 5.5%) i/s - 91.000 in 5.042064s
Enumerable#max 17.539 (± 5.7%) i/s - 88.000 in 5.030514s
Enumerable#minmax 13.086 (± 7.6%) i/s - 66.000 in 5.052537s

From the above benchmark results, it can be seen that there has been an improvement in the run times for the methods.

Internally Ruby has changed the logic by which objects are compared, which results in these methods being optimized. You can have a look at the commits here and here.