Figures with caption inside tabularray (tblr) tables

Question

I am trying to add captions for figures inside a table but am unable to do so. I have looked into this solution but having flexible X columns is not working as described.

The current output looks something like this.

The offending code.

\documentclass[margin=2in]{article}

\usepackage{tabularray}
\usepackage{graphicx}
\usepackage{caption}

\begin{document}
    \begin{figure}[h]
        \begin{tblr}{X[2,r] X[-1,r]}
            \includegraphics[width=2in]{example-image-a}
            \captionof{figure}{Figure A}
            &
            \includegraphics[width=2in]{example-image-b}
        \end{tblr}
    \end{figure}
\end{document}

Error output:

You can't use `\hrule' here except with leaders. \end
Missing number, treated as zero. \end
Illegal unit of measure (pt inserted). \end
Missing \endgroup inserted. \end
Missing } inserted. \end
Use of \??? doesn't match its definition. \end
Extra \endgroup. \end
Too many }'s. \end

I have also tried with caption and caption* in place of captionof. Any help is appretiated.

Answer 1

You could put them in a \parbox:

\documentclass[margin=2in]{article}

\usepackage{tabularray}
\usepackage{graphicx}
\usepackage{caption}

\begin{document}
    \begin{figure}[h]
        \begin{tblr}{X[2,r] X[-1,r]}
            \parbox[t]{\linewidth}{%
            \includegraphics[width=2in]{example-image-a}
            \captionof{figure}{Figure A}}
            &
            \includegraphics[width=2in]{example-image-b}
        \end{tblr}
    \end{figure}
\end{document}

Answer 2

You need to add two libraries: counter (for correct caption numbering), varwidth (for eliminate your error) and tblr option measure = vbox:

\documentclass{article}

\usepackage{graphicx}
\usepackage[skip=1ex]{caption}

\usepackage{tabularray}              % version 2021P
\UseTblrLibrary{counter,varwidth}    % <===

\begin{document}
    \begin{figure}[ht]
\begin{tblr}{colspec={Q[c, wd=2in]  Q[c, wd=2in]},
             measure = vbox}         % <===
\includegraphics[width=\linewidth]{example-image-a}
\caption{Figure A}
    &   \includegraphics[width=\linewidth]{example-image-b} 
\end{tblr}
    \end{figure}
\end{document}

Edit:

Note, for above solution you need to use tabularray package version 2021P, which support/contain libraries counter and varwidth and should include tblr option measure = vbox . Older versions (before 2021N) doesn't support/ enables all aforementioned.

If you have older version of package (it is still in fast development) I recommend you to upgrade it. Beside mentioned recent version has some bug fixes too and also improved documentation.

Instead of Q[c, wd=1in] (width is taken from width of your images), you can use X[c] or X[h]. In this case compilation will throw warnings.