[gumby]

Those cases are the ones for which the explicit return type was intended. And if the deduced type is counterintuitive you could also use the explicit return type (or a comment: there are good arguments for either choice).

But if your argument is "this makes the reader do extra work" then that's an argument against all uses of `auto`. Now I do consider reader clarity a legitimate (and important) design criterion (and argument in code review), but I don't think it is reasonable in this case.

In fact I consider type deduction with auto to be an important element of readability: it tells the reader not to worry about the type and focus on the logic. Then the cases when a type is explicitly specified it tells the reader that it's worth paying attention.