Inside an SV: Strings

• PV (Pointer Values)
• SvPV has char * pointer
• SvPVIV has pointer AND an IV field

    struct xpv {
      char * xpv_pv; /* pointer to malloced string */
      STRLEN xpv_cur; /* length of xpv_pv as a C string */
      STRLEN xpv_len; /* allocated size */
    };