Calculate Maximum of Lengths – TikZ PGF Calculations

Question

How can I calculate a maximum of lengths? I am aware of pgfmath's function max(x_1,x_2,...)

\documentclass[a4paper,draft]{article}
\usepackage{tikz}
\pgfmathparse{max(3,4)}

\begin{document}
\end{document}

But what if I have lengths instead of numbers?

\documentclass[a4paper,draft]{article}

\usepackage{tikz}
\newlength{\foo}
\setlength{\foo}{1cm}

\newlength{\baz}
\setlength{\baz}{1cm}

\pgfmathparse{max(\foo,\baz)}

\newlength{\qux}
\setlength{\qux}{\pgfmathresult}

\pgfmathresult doesn't have a unit of measurement.

Answer 1

The result is actually a length in points (pt) without the unit. You can simply add this unit again:

\setlength{\qux}{\pgfmathresult pt}

There is also the \pgfmathsetlength macro:

\pgfmathsetlength{\qux}{max(\foo,\baz)}