基本反映。价值用法
import "reflect"
value := reflect.ValueOf(4)
// Interface returns an interface{}-typed value, which can be type-asserted
value.Interface().(int) // 4
// Type gets the reflect.Type, which contains runtime type information about
// this value
value.Type().Name() // int
value.SetInt(5) // panics -- non-pointer/slice/array types are not addressable
x := 4
reflect.ValueOf(&x).Elem().SetInt(5) // works