Go map key optimization

map_test.go

package map_test

import (
	"testing"
)

func BenchmarkMapStringKey(b *testing.B) {
	var m map[string]string = make(map[string]string)
	var k string = "key"
	for i := 0; i < b.N; i++ {
		_, _ = m[k]
	}
}

func BenchmarkMapBytesKey(b *testing.B) {
	var m map[string]string = make(map[string]string)
	var k []byte = []byte("key")
	for i := 0; i < b.N; i++ {
		_, _ = m[string(k)]
	}
}

func BenchmarkMapBytesConvertKey(b *testing.B) {
	var m map[string]string = make(map[string]string)
	var k []byte = []byte("key")
	for i := 0; i < b.N; i++ {
		var ks = string(k)
		_, _ = m[ks]
	}
}

results.txt

$ go test -bench=. -benchmem map_test.go
testing: warning: no tests to run
PASS
BenchmarkMapStringKey-4      	300000000	         4.57 ns/op	       0 B/op	       0 allocs/op
BenchmarkMapBytesKey-4       	200000000	         7.00 ns/op	       0 B/op	       0 allocs/op
BenchmarkMapBytesConvertKey-4	100000000	        20.8 ns/op	       0 B/op	       0 allocs/op
ok  	command-line-arguments	13.046s