請看例子：http : //play.golang.org/p/6d4uX15EOQpackage mainimport (    "fmt"    "reflect"    "unsafe")func main() {    c := "foofoofoofoofoofofoofoofoofoofoofoofoofoofoofoofoofoofoofoofoo"    fmt.Printf("c: %T, %d\n", c, unsafe.Sizeof(c))    fmt.Printf("c: %T, %d\n", c, reflect.TypeOf(c).Size())}輸出：c: string, 8 //8 bytes?!c: string, 8這么大的字符串好像不能有這么小的尺寸！怎么了？