forkjo/vendor/github.com/tinylib/msgp/msgp/unsafe.go
2018-05-19 20:49:46 +08:00

41 lines
1 KiB
Go

// +build !purego,!appengine
package msgp
import (
"reflect"
"unsafe"
)
// NOTE:
// all of the definition in this file
// should be repeated in appengine.go,
// but without using unsafe
const (
// spec says int and uint are always
// the same size, but that int/uint
// size may not be machine word size
smallint = unsafe.Sizeof(int(0)) == 4
)
// UnsafeString returns the byte slice as a volatile string
// THIS SHOULD ONLY BE USED BY THE CODE GENERATOR.
// THIS IS EVIL CODE.
// YOU HAVE BEEN WARNED.
func UnsafeString(b []byte) string {
sh := (*reflect.SliceHeader)(unsafe.Pointer(&b))
return *(*string)(unsafe.Pointer(&reflect.StringHeader{Data: sh.Data, Len: sh.Len}))
}
// UnsafeBytes returns the string as a byte slice
// THIS SHOULD ONLY BE USED BY THE CODE GENERATOR.
// THIS IS EVIL CODE.
// YOU HAVE BEEN WARNED.
func UnsafeBytes(s string) []byte {
return *(*[]byte)(unsafe.Pointer(&reflect.SliceHeader{
Len: len(s),
Cap: len(s),
Data: (*(*reflect.StringHeader)(unsafe.Pointer(&s))).Data,
}))
}