How to implement cleveref`s aliascnt method for theorem-like environments?

Question

This answer demonstrates how to use the aliascnt method to create an ineq environment which shares a counter with the equation environment, but which cleveref can nevertheless recognize as a different environment than equation.

The code which the answer uses to define the ineq environment is copied from the code used in latex.ltx to define the equation environment. Consequently, the answer is specific to situations in which it is desirable to define equation-like environments.

However, how can the aliascnt method be used when the new environment to be defined is similar to theorem rather than to equation, as described in this question?

Answer 1

The thing that's wrong about the MWE in the posting referenced by the OP is that the cleveref package is loaded too late, i.e., only after the \newtheorem directives are executed. If the \usepackage{cleveref} is placed after \usepackage{amsthm} and before \newtheorem, the \cref command produces the expected, i.e., correct, output.

FWIW, the need to load the cleveref package before the \newtheorem commands are executed if the amsthm (or ntheorem) package is loaded is mentioned several times in the user guide of the cleveref package. E.g., in section 14.1, "Non-bugs", the second bullet point states [highlighting added]:

Finally, I see no need to incur the hassles of the aliascnt method -- at least not for the use case at hand.

\documentclass{article}
\usepackage{amsthm,cleveref}
\newtheorem{definition}{Definition}
\newtheorem{theorem}[definition]{Theorem}

\begin{document}
\begin{definition}\label{d}
This is a definition.
\end{definition}

\begin{theorem}\label{t}
This is a theorem.
\end{theorem}

Here is a cross-reference to~\cref{t}.
\end{document}