[Tex/LaTex] Make last column take all remaining space in longtable

Question

I want to create a table using longtable where all columns have a fixed length except the last one, which should take all remaining space. The table itself should be full page width.

I tried the following with longtable, but it is not working:

\documentclass{article}

\usepackage{longtable}
\usepackage{tabu}
\usepackage{array}
\usepackage{booktabs}

\setlength\parindent{0pt}
\setlength\LTleft{0pt}
\setlength\LTright{0pt}

\begin{document}

\begin{longtable}[h]{p{2cm}l@{\extracolsep{\fill}}}
\toprule
Icon   & Description \\
\midrule
Icon 1 & Means this and that \\
Icon 2 & Means some other thing \\
\bottomrule
\end{longtable}

\end{document}

With tabu I would achieve something like this as follows:

\begin{tabu} to \textwidth {p{2cm}X}

Here's an online example: https://es.sharelatex.com/project/555e01773b14e98f7d55ed84

How to do the same using longtable?

Edit: I know I can do this with other environments. The question is specifically whether this can be achieved with longtable.

Answer 1

You can use the ltablex package, which brings the functionalities of longtable in tabularx environments:

\documentclass{article}

\usepackage[ nomarginpar]{geometry}%showframe,
\usepackage{ragged2e}
\usepackage{array}
\usepackage{ltablex}
\keepXColumns
\usepackage{booktabs}
\usepackage{lipsum}

\setlength\parindent{0pt}
\setlength\LTleft{0pt}
\setlength\LTright{0pt}
\raggedbottom
\begin{document}

\begin{tabularx}{\linewidth}{p{2cm}>{\arraybackslash}X}
  \caption{A demo of the possibilities of \texttt{ltablex}}
  \\ \toprule
  Icon & Description\medskip
  \endfirsthead
  \midrule
  Icon & Description\medskip% \
  \endhead
  \midrule
  \endfoot
  \bottomrule
  \endlastfoot%\\
         & \lipsum[1] \\
  \midrule
  Icon 1 & Means this and that \lipsum[2] \\
  Icon 2 & Means some other thing\lipsum[3] \\
  Icon 3 & Means this and that \lipsum[4] \\
  Icon 4 & Means some other thing\lipsum[5]
\end{tabularx}

\end{document}