cstring-to-i-benchmark.cr

require "benchmark"

STR = "8675309".cstr


lib LibC
  fun atoi(str : UInt8*) : Int32
end

def crystal
  String.new(STR).to_i
end

def libc
  LibC.atoi(STR)
end

p crystal == libc

n = 10_000_000

Benchmark.bm do |x|
  x.report("crystal") { n.times { crystal }}
  x.report("libc")    { n.times { libc }}
end

output

true
              user     system      total        real
crystal   1.150000   0.230000   1.380000 (  1.139501)
libc      0.000000   0.000000   0.000000 (  0.000001)