pbuf.go
func NewPointerRingBuf(sliceN int) *PointerRingBuf {
	n := sliceN
	r := &PointerRingBuf{
		N:        n,
		Beg:      0,
		Readable: 0,
	}
	r.A = make([]interface{}, n, n)

	return r
}
func NewPointerRingBuf(sliceN int) *PointerRingBuf {
	n := sliceN
	r := &PointerRingBuf{
		N:        n,
		Beg:      0,
		Readable: 0,
	}
	r.A = make([]interface{}, n, n)

	return r
}
// constructor. NewPointerRingBuf will allocate internally
// a slice of size sliceN