Extension for Ruby written in Crystal via gem

Make sure installed crystal first. Then add gem ruby_ext_in_crystal_math to Gemfile

gem 'ruby_ext_in_crystal_math', git: 'git@github.com:gaar4ica/ruby_ext_in_crystal_math.git'

and execute bundle install

Benchmarking

$ irb
2.1.6 :001 > require 'common_math'
 => true
2.1.6 :002 > CommonMath.measure
       user     system      total        real
rb  7.940000   0.010000   7.950000 (  7.963207)
cr  0.430000   0.000000   0.430000 (  0.431696)
 => nil