Rule 0-1-3/0-1-4/0-1-5 and (template) class members

[misra cpp]

The basic answer to all these queries is that every definition in the program must be used somewhere, or conversely, it should not be possible to remove a definition from the code and still have the program compile.

So for a template class, each member of the class must be used by at least one instantiation of the template.