Function PackTuple

tuple.go:43–66

PackTuple returns a new *Tuple which contains the arguments. This tuple is ready to use. Return value: New Reference.

(items ...*Base)

//
// Return value: New Reference.
func PackTuple(items ...*Base) *Tuple {
	ret := C.PyTuple_New(C.Py_ssize_t(len(items)))

	// Since the ob_item array has a size of 1, Go won't let us index more than
	// a single entry, and if we try and use our own local type definition with
	// a flexible array member then cgo converts it to [0]byte which is even
	// less useful.  So, we resort to pointer manipulation - which is
	// unfortunate, as it's messy in Go.

	// base is a pointer to the first item in the array of PyObject pointers.
	// step is the size of a PyObject * (i.e. the number of bytes we need to add
	// to get to the next item).
	base := unsafe.Pointer(&(*C.PyTupleObject)(unsafe.Pointer(ret)).ob_item[0])
	step := uintptr(C.tupleItemSize())

	for _, item := range items {
		item.Incref()
		*(**C.PyObject)(base) = item.c()

		// Move base to point to the next item, by incrementing by step bytes
		base = unsafe.Pointer(uintptr(base) + step)
	}
	return newTuple(ret)
}

func (t *Tuple) CheckExact() bool {
	ret := C.tupleCheckE(t.c())