In tikz double arrow head, increase the size of only one head

Question

I have diagrams with arcs with heads produced with \draw[<__|-, ...] or \draw[<<__|-, ...], like in this MWE:

\documentclass[tikz]{standalone}
\usetikzlibrary[positioning]
\begin{document}
  \begin{tikzpicture}
    \node(A){A}; \node(B)[right=2cm of A]{B};
    \draw[<<__|-|__>, very thick] (A) -- (B);
  \end{tikzpicture}
\end{document}

It is possible to increase only the length of the vertical bar? How it can be done? The ideal would be to define a style to apply to all the cases in my diagrams.

Thank you very much!

Answer 1

With arrows.meta you can control all aspects of these arrows. I added two bars of different lengths (or widths) to the example.

\documentclass[tikz]{standalone}
\usetikzlibrary[positioning,arrows.meta]
\begin{document}
  \begin{tikzpicture}
    \node(A){A}; \node(B)[right=2cm of A]{B};
    \draw[{<<__Bar[width=1.5ex]}-{Bar[width=2ex]__>}, very thick] (A) -- (B);
  \end{tikzpicture}
\end{document}

Needless to say that you can also manipulate the other arrows in similar ways.