SV xpv +--------+ +-----+ | ANY |-+ ->| PVX |---> char[] | REFCNT | \ / | CUR | | FLAGS | \ / | LEN | +--------+ \/ +-----+ /\ SV / \ xpv +--------+ / \ +-----+ | ANY |-+ ->| PVX |---> char[] | REFCNT | | CUR | | FLAGS | | LEN | +--------+ +-----+