\begin{Verbatim}[commandchars=\\\{\},codes={\catcode`\$=3\catcode`\^=7\catcode`\_=8\relax}]
\PYG{c+c1}{// returns the number of elements in the list}
\PYG{k+kt}{int}\PYG{+w}{ }\PYG{n+nf}{length}\PYG{p}{(}\PYG{n}{listElement}\PYG{o}{*}\PYG{+w}{ }\PYG{n}{list}\PYG{p}{);}

\PYG{c+c1}{// push a new element onto the head of a list and update the list reference using side effects}
\PYG{k+kt}{void}\PYG{+w}{ }\PYG{n+nf}{push}\PYG{p}{(}\PYG{n}{listElement}\PYG{o}{**}\PYG{+w}{ }\PYG{n}{list}\PYG{p}{,}\PYG{+w}{ }\PYG{k+kt}{char}\PYG{o}{*}\PYG{+w}{ }\PYG{n}{data}\PYG{p}{,}\PYG{+w}{ }\PYG{k+kt}{size\PYGZus{}t}\PYG{+w}{ }\PYG{n}{size}\PYG{p}{);}

\PYG{c+c1}{// pop an element from the head of a list and update the list reference using side effects}
\PYG{n}{listElement}\PYG{o}{*}\PYG{+w}{ }\PYG{n+nf}{pop}\PYG{p}{(}\PYG{n}{listElement}\PYG{o}{**}\PYG{+w}{ }\PYG{n}{list}\PYG{p}{);}

\PYG{c+c1}{// enque a new element onto the head of the list and update the list reference using side effects}
\PYG{k+kt}{void}\PYG{+w}{ }\PYG{n+nf}{enqueue}\PYG{p}{(}\PYG{n}{listElement}\PYG{o}{**}\PYG{+w}{ }\PYG{n}{list}\PYG{p}{,}\PYG{+w}{ }\PYG{k+kt}{char}\PYG{o}{*}\PYG{+w}{ }\PYG{n}{data}\PYG{p}{,}\PYG{+w}{ }\PYG{k+kt}{size\PYGZus{}t}\PYG{+w}{ }\PYG{n}{size}\PYG{p}{);}

\PYG{c+c1}{// dequeue an element from the tail of the list}
\PYG{n}{listElement}\PYG{o}{*}\PYG{+w}{ }\PYG{n+nf}{dequeue}\PYG{p}{(}\PYG{n}{listElement}\PYG{o}{*}\PYG{+w}{ }\PYG{n}{list}\PYG{p}{);}
\end{Verbatim}