func (b *Float64RingBuf) Earliest() (v float64, ok bool) {
	if b.Readable == 0 {
		return
	}

	return b.A[b.Beg], true
}
func (b *Float64RingBuf) Earliest() (v float64, ok bool) {
	if b.Readable == 0 {
		return
	}

	return b.A[b.Beg], true
}
// Earliest returns the earliest written value v. ok will be
// true unless the ring is empty, in which case ok will be false,
// and v will be zero.