How to draw a \mapsto in TikZ?

Question

Does anyone know how to draw a line which looks like \mapsto by using \draw[...]... in TikZ?

Answer 1

This uses the solution from How to make an arrow bigger and change its color in TikZ? to adjust the size of the arrow.

\begin{document}
\[a \mapsto b\]

\begin{tikzpicture}
\draw [red, |->, decoration={markings,mark=at position 1 with {\arrow[scale=1.7,red]{>}}},
    postaction={decorate},
    shorten >=0.4pt
] (0,0) node [black,left] {$a$} -- (0.4,0) node [black,right] {$b$};
\end{tikzpicture}
\end{document}