If there's no set magic attached, SvSETMAGIC(sv) does nothing. If there is, SvSETMAGIC(sv) makes it work. Knowing you and having just seen how you plan to use this, I know you'll simply assume there's no magic attached to the scalar.
in reply to Re^4: XS: returning a 64-bit unsigned int?
in thread XS: returning a 64-bit unsigned int?