tikz-cd equivalent to the xy-pic command \ar@{-}

Question

How do I make the diagram

X - Y -> Z

with tikz-cd?

With xy-pic, I would enter

\xymatrix{ X \ar@{-}[r] & Y \ar[r] & Z }

I tried

\begin{tikzcd} X \ar[no head]{r} & Y \ar{r} & Z \end{tikzcd}

but it didn't work.

Note that

\begin{tikzcd} X \ar[two heads]{r} & Y \ar{r} & Z \end{tikzcd}

produces

X ->> Y -> Z

"as it should".

In other words:

What is the tikz-cd equivalent to the xy-pic command \ar@{-}?

Thank you very much in advance for your help.

EDIT. Peter Jansson kindly asked me to provide a Minimal Working Example (MWE). So here is what works:

\documentclass{article}
\usepackage[all]{xy}
\usepackage{tikz-cd}
\begin{document}
$$
\xymatrix{ X \ar@{-}[r] & Y\ar[r] & Z}
$$
$$
\begin{tikzcd} 
X \ar[two heads]{r} & Y \ar{r} & Z 
\end{tikzcd}
$$
\end{document}

Here is what doesn't work:

\documentclass{article}
\usepackage{tikz-cd}
\begin{document}
$$
\begin{tikzcd} 
X \ar[no head]{r} & Y \ar{r} & Z 
\end{tikzcd}
$$
\end{document}

I get the error message

! Package pgfkeys Error: 
I do not know the key '/tikz/no head' 
and I am going to ignore it. 
Perhaps you misspelled it.

This doesn't surprise me because I just tried to guess at a possible command. But I hope that there is a simple way to do this.

Answer 1

Just use the optional argument to \ar that allows for specifying the arrow's shape, shift and whatnot:

\documentclass{article}
\usepackage{tikz-cd}
\begin{document}
\[
\begin{tikzcd} 
X \ar[-]{r} & Y \ar{r} & Z 
\end{tikzcd}
\]
\end{document}

Never use $$ in LaTeX.