I'm having a look at Go, which looks quite promising. I am trying to figure out how to get the size of a go struct, for example something like
type Coord3d struct {
X, Y, Z int64
}
Of course I know that it's 24 bytes, but I'd like to know it programmatically..
Do you have any ideas how to do this ?
import unsafe "unsafe"
/* Structure describing an inotify event. */
type INotifyInfo struct {
Wd int32 // Watch descriptor
Mask uint32 // Watch mask
Cookie uint32 // Cookie to synchronize two events
Len uint32 // Length (including NULs) of name
}
func doSomething() {
var info INotifyInfo
const infoSize = unsafe.Sizeof(info)
...
}
NOTE: The OP is mistaken. The unsafe.Sizeof does return 24 on the example Coord3d struct. See comment below.
binary.TotalSize is also an option, but note there's a slight difference in behavior between that and unsafe.Sizeof: binary.TotalSize includes the size of the contents of slices, while unsafe.Sizeof only returns the size of the top level descriptor. Here's an example of how to use TotalSize.
package main
import (
"encoding/binary"
"fmt"
"reflect"
)
type T struct {
a uint32
b int8
}
func main() {
var t T
r := reflect.ValueOf(t)
s := binary.TotalSize(r)
fmt.Println(s)
}