package main

import (
	"fmt"
	"unsafe"
)

type Data struct {
	Value  uint32   // 4 bytes
	Label  [10]byte // 10 bytes
	Active bool     // 1 byte
	// padded with 1 byte to make it align
}

func (d Data) String() string {
	return fmt.Sprintf(`{Value:%d, Label:%s, Active: %v}`, d.Value, string(d.Label[:]), d.Active)
}

const (
	dataSize = unsafe.Sizeof(Data{})
	dataSizeLiteral = 16
)

func main() {
	fmt.Println(dataSize)
	// use a literal value for array size: no go vet error
	incomingData2 := [16]byte{0, 132, 95, 237, 80, 104, 111, 110, 101, 0, 0, 0, 0, 0, 1, 0}
	fmt.Println(incomingData2)

	// use a constant based on unsafe.Sizeof for array size: ERROR INCORRECTLY REPORTED BY GO VET
	incomingData := [dataSize]byte{0, 132, 95, 237, 80, 104, 111, 110, 101, 0, 0, 0, 0, 0, 1, 0}
	fmt.Println(incomingData)

	// double check that the values aren't different
	fmt.Println(incomingData == incomingData2)
	fmt.Println(dataSize == 16)

	// constant has literal value: no go vet error
        incomingData3 := [dataSizeLiteral]byte{0, 132, 95, 237, 80, 104, 111, 110, 101, 0, 0, 0, 0, 0, 1, 0}
        fmt.Println(incomingData3)
}

$ go vet main.go
# command-line-arguments
vet: ./main.go:31:92: index 15 is out of bounds (>= 15)