References

• Pointer to another SV

    struct xrv {
      SV * xrv_rv; /* pointer to another SV */
    }
  

• So $a = \$b is

    sv_upgrade(a, SVt_RV);	/* make sure it's an RV */
    a->sv_any->xrv_rv = b;
  

• Rarely access fields directly--better to use macros

    sv_upgrade(a, SVt_RV); /* Make sure a is an RV */
    SvRV(a) = b;