キャプチャするしない

regexp.go

package regexp

import (
	"regexp"
	"testing"
)

func BenchmarkRegexp1(b *testing.B) {
	re := regexp.MustCompile(`(iTunes)/(\d+)\.(\d+)`)
	for i := 0; i < b.N; i++ {
		re.MatchString("iTunes/12.7 (Macintosh; OS X 10.11.6) AppleWebKit/601.7.8")
		re.MatchString("Mozilla/5.0 (Macintosh; U; Intel Mac OS X; en-US) AppleWebKit/533.3 (KHTML, like Gecko) cXensebot/1.1a; +http://www.cxense.com/bot.html/0.1 Safari/533.3")
	}
}

func BenchmarkRegexp2(b *testing.B) {
	re := regexp.MustCompile(`iTunes/\d+\.\d+`)
	for i := 0; i < b.N; i++ {
		re.MatchString("iTunes/12.7 (Macintosh; OS X 10.11.6) AppleWebKit/601.7.8")
		re.MatchString("Mozilla/5.0 (Macintosh; U; Intel Mac OS X; en-US) AppleWebKit/533.3 (KHTML, like Gecko) cXensebot/1.1a; +http://www.cxense.com/bot.html/0.1 Safari/533.3")
	}
}

result.txt

$ go test -bench=. -benchmem                                                                             [~/src/github.com/yoppi/go/regexp]
goos: darwin
goarch: amd64
pkg: github.com/yoppi/go/regexp
BenchmarkRegexp1-4       3000000               774 ns/op               0 B/op          0 allocs/op
BenchmarkRegexp3-4       3000000               521 ns/op               0 B/op          0 allocs/op
PASS
ok      github.com/yoppi/go/regexp      4.922s