TYPEMAP
Bar *		O_Inline_CPP_Class
Foo *		O_Inline_CPP_Class

OUTPUT
O_Inline_CPP_Class
    sv_setref_pv( $arg, CLASS, (void*)$var );

INPUT
O_Inline_CPP_Class
    if (sv_isobject($arg) && (SvTYPE(SvRV($arg)) == SVt_PVMG)) {
        $var = ($type)SvIV((SV*)SvRV( $arg ));
    }
    else {
        warn ( \"${Package}::$func_name() -- $var is not a blessed reference\" );
        XSRETURN_UNDEF;
    }

