This question is similar to this one, only I want to convert a pointer and a length to a fixed-size Golang array.
For a slice, the solution was to create a struct with the relevant information, and cast it directly, as follows:
// Slice memory layout
var sl = struct {
addr uintptr
len int
cap int
}{addr, length, length}
// Use unsafe to turn sl into a []byte.
b := *(*[]byte)(unsafe.Pointer(&sl))
How would you create an array for that specified memory instead?
It's almost the same as with slices but since Go arrays are just values laid out sequentially as opposed to being represented by a pointer, cap, and len like slices are, you don't need to define the array's memory layout.
package main
import (
"fmt"
"reflect"
"unsafe"
)
var data = []byte(`foobar`)
func main() {
rv := reflect.ValueOf(data)
ptr := rv.Pointer()
b := *(*[3]byte)(unsafe.Pointer(ptr))
fmt.Printf("%T %q\n", b, b)
}
3 is meant to serve as an example that it doesn't have to be the same as the original array's len, it's up to you what size the new array should have, you could set it to 10 but the data after the first 6 elements might be garbage.c is not an array but a pointer to an array, and it's a pointer to the same address as the data slice, just different in type (play.golang.org/p/N7P3XonBCq). As soon as you dereference it (*c) you get a copy of its contents play.golang.org/p/fSLGpf8VnS. It's up to you which one you prefer.