}
}

func (b *protobuf) boolOpt(tag int, x bool) {
	if !x {
		return
	}
	b.bool(tag, x)
}

type msgOffset int

func (b *protobuf) startMessage() msgOffset {
	b.nest++
	return msgOffset(len(b.data))
}

func (b *protobuf) endMessage(tag int, start msgOffset) {
	n1 := int(start)
	n2 := len(b.data)
	b.length(tag, n2-n1)
	n3 := len(b.data)
	copy(b.tmp[:], b.data[n2:n3])