char *			T_PV
const char *		T_PV
void *			O_OBJECT
int			T_IV

INPUT
T_IV
	$var = (((SvIOK($arg)) || (SvNOK($arg)) || ((SvFLAGS($arg) & (SVf_OK & ~SVf_ROK)) && looks_like_number($arg))) ? ($type)SvIV($arg) : -1)
T_PV
	$var = ((SvFLAGS($arg) & (SVf_OK & ~SVf_ROK)) ? ($type)SvPV_nolen($arg) : NULL)
O_OBJECT
	$var = (sv_isobject($arg) ? ($type)SvIV((SV*)SvRV( $arg )) : NULL);