Golang - detect bitness

prog.go

package main

import (
	"fmt"
	"unsafe"
)

func main() {
  // way 1
	const is64Bit = uint64(^uintptr(0)) == ^uint64(0)

  // way 2 - 64bit pointer has size of 8
  ptrSz := unsafe.Sizeof(unsafe.Pointer(nil))
  fmt.Println("is 64 bit:", is64Bit, ptrSz == 8)
}