I could get on board with the idea that we should discourage people from using exception handling in situations where return codes would be a better solution but you have not established that return codes are almost always better than exceptions for almost all programmers. This is quite different from the situation with smart pointers versus manual memory management.

In general, yes, I agree with you, but I do not understand then why expected<> is not still in the standard.

Note also that the question of the probability of the "exceptional" events occurring is not relevant here, except perhaps in a performance-sensitive context. Whether you want to make that iterator throw an exception on an I/O error, or return expected<char, E>, regardless of the fraction of the time that the error path is taken, is a stylistic choice.

Yes and no. By saying "use exceptions for exceptional situations"