expected: references

[timrae]

Hi, I really appreciate all your work on this proposal, I really think it would be great if std::expected made it into the standard.

I have one "feature request": In the current proposal you say:

This proposal doesn't include expected references as optional [C++17] doesn't include references either. We need a future proposal.

I don't think this is a meaningful comparison. optional<T&> adds no extra functionality compared to T*, so I assume the committee probably thought it was a waste of time. On the other hand, expected<T&, Error> clearly adds additional functionality compared to T*.

In my company we have tried to take an approach similar to std::expected, packaging an optional together with an error, but it didn't get received well because of the lack of references. Nobody wants to use std::expected<std::reference_wrapper<T>, Error> as the return type to a function in an API.

[viboes]

Thanks for your support.

I believe we need a separate proposal with a good motivation and an implementation. This is not in my priority list at this moment.

I would appreciate if someone else did it. There are some things I believe the paper should explain. Why we don't have vector<T&>? How often do we need it an in which cases?