Memoir sub table numbering wrong

Question

I am using sub tables and it seems because I but the table caption above I get the wrong number in the sub table references. How can I fix this?

I am pretty sure it is related to the package float package. I am very interested in both quick hacks to fix this specific problem with this combination and in a better set of tools that I can use the next time to avoid these sort of problem all together.

Here is what I am doing:

\documentclass[11pt,a4paper]{memoir}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{float}

\newsubfloat{table}

\begin{document}

\begin{table}[H]
    \centering
    \begin{minipage}{0.9\textwidth}
    \caption{Multple tables\label{theTable}}
    \begin{minipage}{0.5\textwidth}
        \subcaption{A sub table\label{firstSubTable}}
    \end{minipage}
    \begin{minipage}{0.5\textwidth}
        \subcaption{Second sub table\label{secondSubTable}}
    \end{minipage}
    \end{minipage}
\end{table}

Referencing the table (Table~\ref{theTable}) seems right but in referencing the
sub tables (Table~\ref{firstSubTable} and Table~\ref{secondSubTable}) they get
the wrong table number.

\end{document}

And how it looks:

Answer 1

In my opinion, you encountered a bug and you should properly report it. A workaround (stupid but working) is to add this at the end of your preamble:

\makeatletter
\let\X@old@caption\caption
\def\X@caption@minusone{\expandafter\advance\csname c@\@captype\endcsname-1 }
\def\X@caption@br[#1]#2{\X@old@caption[#1]{#2}\X@caption@minusone}
\def\X@caption@nobr#1{\X@old@caption{#1}\X@caption@minusone}
\def\caption{\@ifnextchar[\X@caption@br\X@caption@nobr}
\makeatother

How does it work: Originally, \caption globally increases the counter by one. We, using the low-level macro \advance decrease is locally, which means that inside the float, it's unmodified, but outside, it will have the correct value (as you can check by adding a 2nd table). The rest are tweaks needed because \caption has an optional argument.

Answer 2

Float messes with \caption for some strange reason, this seems to do the trick

\let\stdcaption\caption
\usepackage{float}
\let\caption\stdcaption

basically we restore the memoir \caption after loading float. As already mentioned, I do not see the need for using the float package

Answer 3

I don't know if I understand the problem. Can't you just do it without the float package? If you simply comment out the float package it works.

\documentclass[11pt,a4paper]{memoir}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
% \usepackage{float}
\newsubfloat{table}
\begin{document}
\begin{table}[htp]
\caption{Multple tables\label{theTable}}
\begin{minipage}{.4\textwidth}
\centering
Table 1
\subcaption{A sub table\label{firstSubTable}}
\end{minipage}
\hfill
\begin{minipage}{.4\textwidth}
\centering
Table 2
\subcaption{Second sub table\label{secondSubTable}}
\end{minipage}
\end{table}
Referencing the table (Table~\ref{theTable}) seems right but in referencing the
sub tables (Table~\ref{firstSubTable} and Table~\ref{secondSubTable}) they get
the wrong right number.
\end{document}