Shorten both ends of a line with one key

Question

Consider the following snippet:

\begin{tikzpicture}
    \def\ptRad{2pt}
    \fill (0,0) circle (\ptRad);
    \fill (1,1) circle (\ptRad);
    \draw[<->, shorten <=\ptRad,shorten >=\ptRad] (0,0) -- (1,1);  
\end{tikzpicture}

Is there a way to use only one shortening key for both ends at the same time?

Answer 1

You can define your own style that sets the shorten for both ends at the same time:

\tikzset{ shorten <>/.style={ shorten >=#1, shorten <=#1 } }