}
	// need to remember addr and h for unmapping
	return Data{f, unsafe.Slice((*byte)(unsafe.Pointer(addr)), size), h}, nil
}

func munmapFile(d Data) error {
	err := windows.UnmapViewOfFile(uintptr(unsafe.Pointer(&d.Data[0])))
	x, ok := d.Windows.(windows.Handle)
	if ok {
		windows.CloseHandle(x)
	}
	d.f.Close()
	return err

	procSetHandleInformation               = modkernel32.NewProc("SetHandleInformation")
	procTerminateProcess                   = modkernel32.NewProc("TerminateProcess")
	procUnmapViewOfFile                    = modkernel32.NewProc("UnmapViewOfFile")
	procUpdateProcThreadAttribute          = modkernel32.NewProc("UpdateProcThreadAttribute")
	procVirtualLock                        = modkernel32.NewProc("VirtualLock")

//sys	MapViewOfFile(handle Handle, access uint32, offsetHigh uint32, offsetLow uint32, length uintptr) (addr uintptr, err error)
//sys	UnmapViewOfFile(addr uintptr) (err error)
//sys	FlushViewOfFile(addr uintptr, length uintptr) (err error)
//sys	VirtualLock(addr uintptr, length uintptr) (err error)
//sys	VirtualUnlock(addr uintptr, length uintptr) (err error)

	procUnlockFileEx                                         = modkernel32.NewProc("UnlockFileEx")
	procUnmapViewOfFile                                      = modkernel32.NewProc("UnmapViewOfFile")
	procUpdateProcThreadAttribute                            = modkernel32.NewProc("UpdateProcThreadAttribute")
	procVirtualAlloc                                         = modkernel32.NewProc("VirtualAlloc")

//sys	MapViewOfFile(handle Handle, access uint32, offsetHigh uint32, offsetLow uint32, length uintptr) (addr uintptr, err error)
//sys	UnmapViewOfFile(addr uintptr) (err error)
//sys	FlushViewOfFile(addr uintptr, length uintptr) (err error)
//sys	VirtualLock(addr uintptr, length uintptr) (err error)
//sys	VirtualUnlock(addr uintptr, length uintptr) (err error)

		{"Umask", Func, 0},
		{"Uname", Func, 0},
		{"Undelete", Func, 0},
		{"UnixCredentials", Func, 0},
		{"UnixRights", Func, 0},
		{"Unlink", Func, 0},
		{"Unlinkat", Func, 0},
		{"UnmapViewOfFile", Func, 0},
		{"Unmount", Func, 0},
		{"Unsetenv", Func, 4},
		{"Unshare", Func, 0},
		{"UserInfo10", Type, 0},
		{"UserInfo10.Comment", Field, 0},
		{"UserInfo10.FullName", Field, 0},