Package fixltx2e Warning: fixltx2e is not required with releases after 2015
(fixltx2e)                All fixes are now in the LaTeX kernel.
(fixltx2e)                See the latexrelease package for details.

begingroupexpandafterexpandafterexpandafterendgroup
expandafterifxcsname IncludeInReleaseendcsnamerelax
  usepackage{fixltx2e}
fi

documentclass{article}

makeatletter%
defgetversion{expandafterget@versionpdftexbanner@nil}%
defget@version#1201#2)#3@nil{defTeXLiveVersion{201#2}}%
makeatother%
getversion%

ifnumTeXLiveVersion<2015relax%
    usepackage{fixltx2e}%
    typeout{*** Included fixltx2e}
elese
    typeout{*** DId NOT Included fixltx2e}
fi%


begin{document}
xxx
end{document}