preconvert vs in place conversion benchmark

gistfile1.txt

package main

import (
    "testing"
)

type myKindaString string

// do nothing ops, no we don't need three
func doSumptin(a string) {}

func BenchmarkConversion(b *testing.B) {
    var mine myKindaString
    mine = "crapola"
    for n := 0; n < b.N; n++ {
        doSumptin(string(mine))
    }
}

func BenchmarkPreConvert(b *testing.B) {
    var mine myKindaString
    mine = "sumtin"
    sMine := string(mine)
    for n := 0; n < b.N; n++ {
        doSumptin(sMine)
    }
}

$ go test -bench=.
goos: darwin
goarch: amd64
BenchmarkConversion-8 2000000000 0.30 ns/op
BenchmarkPreConvert-8 2000000000 0.60 ns/op