union.go

package main

// #include <windows.h>
// #include <winuser.h>
import "C"

// http://msdn.microsoft.com/en-us/library/windows/desktop/ms646270(v=vs.85).aspx
// typedef struct tagINPUT {
//   DWORD type;
//   union {
//     MOUSEINPUT    mi;
//     KEYBDINPUT    ki;
//     HARDWAREINPUT hi;
//   };
// } INPUT, *PINPUT;

func main() {
  var input C.INPUT
	var keybdinput C.KEYBDINPUT
	input._type = 1 // ok!
	// input.ki = keybdinput // input.ki undefined (type C.INPUT has no field or method ki)
	// input.union_ki = keybdinput // input.union_ki undefined (type C.INPUT has no field or method union_ki)
}