package main

import "fmt"
import "unsafe"

type Data struct {
    Col1 byte
    Col2 int
    Col3 string
    Col4 int
}

func main() {
    var v Data

    fmt.Println(unsafe.Sizeof(v))

    fmt.Println("----")

    fmt.Println(unsafe.Alignof(v.Col1))
    fmt.Println(unsafe.Alignof(v.Col2))
    fmt.Println(unsafe.Alignof(v.Col3))
    fmt.Println(unsafe.Alignof(v.Col4))

    fmt.Println("----")

    fmt.Println(unsafe.Offsetof(v.Col1))
    fmt.Println(unsafe.Offsetof(v.Col2))
    fmt.Println(unsafe.Offsetof(v.Col3))
    fmt.Println(unsafe.Offsetof(v.Col4))

    fmt.Println("----")

    v.Col1 = 98
    v.Col2 = 77
    v.Col3 = "1234567890abcdef"
    v.Col4 = 23

    fmt.Println(unsafe.Sizeof(v))

    fmt.Println("----")

    x := unsafe.Pointer(&v)

    fmt.Println(*(*byte)(x))
    fmt.Println(*(*int)(unsafe.Pointer(uintptr(x) + unsafe.Offsetof(v.Col2))))
    fmt.Println(*(*string)(unsafe.Pointer(uintptr(x) + unsafe.Offsetof(v.Col3))))
    fmt.Println(*(*int)(unsafe.Pointer(uintptr(x) + unsafe.Offsetof(v.Col4))))
}


//go/4424