a Pitfall of slice in golang

slice.go

package main

import (
	"fmt"
	"strings"
	"unsafe"
)

func main() {
	s := make([]int, 10, 20)

	size := unsafe.Sizeof(0)
	fmt.Printf("s address:%p\n", &s)
	fmt.Printf("%x\n", *(*uintptr)(unsafe.Pointer(&s)))
	fmt.Println("s len:",*(*int)(unsafe.Pointer(uintptr(unsafe.Pointer(&s)) + size)))
	fmt.Println("s cap:",*(*int)(unsafe.Pointer(uintptr(unsafe.Pointer(&s)) + size*2)))

	slice(s)

	s1 := s
	fmt.Printf("s1 origin:%p\n", &s1)
	fmt.Printf("%x\n", *(*uintptr)(unsafe.Pointer(&s1)))
	fmt.Println(*(*int)(unsafe.Pointer(uintptr(unsafe.Pointer(&s1)) + size)))
	fmt.Println(*(*int)(unsafe.Pointer(uintptr(unsafe.Pointer(&s1)) + size*2)))

	fmt.Println(strings.Repeat("-", 50))

	*(*int)(unsafe.Pointer(uintptr(unsafe.Pointer(&s1)) + size)) = 20

	fmt.Printf("%x\n", *(*uintptr)(unsafe.Pointer(&s)))
	fmt.Println(*(*int)(unsafe.Pointer(uintptr(unsafe.Pointer(&s)) + size)))
	fmt.Println(*(*int)(unsafe.Pointer(uintptr(unsafe.Pointer(&s)) + size*2)))

	fmt.Printf("s1 large:%x\n", *(*uintptr)(unsafe.Pointer(&s1)))
	fmt.Println(*(*int)(unsafe.Pointer(uintptr(unsafe.Pointer(&s1)) + size)))
	fmt.Println(*(*int)(unsafe.Pointer(uintptr(unsafe.Pointer(&s1)) + size*2)))

	fmt.Println("s:",s)
	fmt.Println("s1:",s1)
}

func slice(s []int) {
	s[9]=1
	s=append(s,12)
	ss:=make([]int,12)
	s=append(s,ss...)

	s[11]=19

	size := unsafe.Sizeof(0)
	fmt.Printf("func address:%p\n", &s)
	fmt.Printf("%x\n", *(*uintptr)(unsafe.Pointer(&s)))
	fmt.Println("func len:",*(*int)(unsafe.Pointer(uintptr(unsafe.Pointer(&s)) + size)))
	fmt.Println("func cap:",*(*int)(unsafe.Pointer(uintptr(unsafe.Pointer(&s)) + size*2)))

}