マルチバイトを考慮したreverse

gistfile1.go

package tool

import (
	"bytes"
)

func Reverse(s string) string {
	runes := make([]rune, 0, 10)
	for _, r := range s {
		runes = append(runes, r)
	}
	var buf bytes.Buffer
	for i := len(runes) - 1; i >= 0; i-- {
		if _, err := buf.WriteRune(runes[i]); err != nil {
			return "error"
		}
	}

	return  buf.String()
}