1// compile 2 3// Copyright 2023 The Go Authors. All rights reserved. 4// Use of this source code is governed by a BSD-style 5// license that can be found in the LICENSE file. 6 7package main 8 9import ( 10 "fmt" 11 "reflect" 12 "unsafe" 13) 14 15var slice = []byte{'H', 'e', 'l', 'l', 'o', ','} 16 17func main() { 18 ptr := uintptr(unsafe.Pointer(&slice)) + 100 19 header := (*reflect.SliceHeader)(unsafe.Pointer(ptr)) 20 header.Data += 1 21 fmt.Printf("%d %d\n", cap(slice), header.Cap) 22} 23