$ go get -u github.com/typa01/go-utils

import (
	tsgutils "github.com/typa01/go-utils"
)

	str1 := tsgutils.NewString("13990521234")
	str2 := tsgutils.NewString("14")
	str3 := str1.Substring(0, 2).Append(str2).AppendString("520")
	println(str1.ToString())
	println(str2.ToString())
	println(str3.ToString())

	builder := NewStringBuilder()
	builder.Append("a").Append("b").Append("c")
	str := builder.ToString()

func (user *User) Rows2struct(rows *mysql.Rows) {
	var users []User
	builder := tsgutils.NewInterfaceBuilder()
	for rows.Next() {
		builder.Clear()
		builder.Append(&user.Host).Append(&user.User)
		builder.Append(&user.AuthenticationString)
		err := rows.Scan(builder.ToInterfaces()...)
		tsgutils.CheckAndPrintError("MySQL query rows scan error", err)
		users = append(users, *user)
	}
	if rows != nil {
		defer rows.Close()
	}
	user.Users = users
}