Hello,

I've been trying to work out if the current expl3 has anything like
\patchcmd from etoolbox.  Will suggested looking at the various \tlp_
... macros.  However, even a simple two-part test in this way fails:

\documentclass{article}
\usepackage{expl3}
\CodeStart
\cs_if_really_exist:cT{thanks}{
  \tlp_if_in:NnT\thanks{\footnotemark}{
    % Do something
  }
  \tlp_if_in:NnT\thanks{\footnotetext}{
    % Also do something
  }
}
\CodeStop
\begin{document}
\end{document}

I guess I'm abusing the functions.  So have I missed something obvious?
 The ability to patch existing functions is very handy.
-- 
Joseph Wright