[boost] [review] Review of Outcome (starts Fri-19-May)

Subject: [boost] [review] Review of Outcome (starts Fri-19-May)
From: charleyb123 . (charleyb123_at_[hidden])
Date: 2017-05-19 13:43:26

Hi Everyone,

The formal review of Niall Douglas' Outcome library starts today
(Fri-19-May) and continues until Sun-28-May.

Your participation is encouraged, as the proposed library is uncoupled and
focused, and reviewers don't need to be domain experts to appreciate the
potential usefulness of the library and to propose improvements.  Everyone
needs (and has suffered) error handling, and can compose an opinion on that
topic.

Outcome is a header-only C++14 library providing expressive and type-safe
ultra-lightweight error handling, suitable for low-latency code bases.

Key features:

*- Makes using std::error_code from C++11's <system_error> more convenient
and safe
*- Provides high-quality implementation of proposed std::expected<T,E> (on
C++20 standards track)
*- Good focus on low-latency (with tests and benchmarks)
*- Error-handling algorithmic composition with-or-without C++ exceptions
enabled
*- No dependencies (not even on Boost)

This review is timely, as C++17 brings us std::optional<T>.  The upcoming
std::expected<T,E> (an implementation provided in Outcome) is a
generalization of std::optional<T> that provides a <success|fail> value,
where the unhappy result is a 'std::error_code' or an instance of
"your-chosen-error-type".

The library further provides 'outcome<T,error-code,exception-ptr>' for
handling <success|error|exception> to safely wrap throwing APIs.

Documentation:
  https://ned14.github.io/boost.outcome/index.html

ACCU 2017 talk including design rationale:
  https://www.youtube.com/watch?v=XVofgKH-uu4

GitHub:
  https://github.com/ned14/boost.outcome

Latest tarball:
  https://github.com/ned14/boost.outcome/releases/download/
boost_peer_review3/boost.outcome-v1.0-source-201705111650.tar.xz

Note:  Tarball might be easiest; but if you want to clone from GitHub
directly, after the clone you should run the following command to get the
source zip exactly:  git submodule update --init --recursive

Please post your comments and review to the boost mailing list
(preferably), or privately to the Review Manager (to me ;-). Here are some
questions you might want to answer in your review:

- What is your evaluation of the design?

- What is your evaluation of the implementation?

- What is your evaluation of the documentation?

- What is your evaluation of the potential usefulness of the library?

- Did you try to use the library? With what compiler? Did you have any
problems?

- How much effort did you put into your evaluation? A glance? A quick
reading? In-depth study?

- Are you knowledgeable about the problem domain?

And most importantly:

- Do you think the library should be accepted as a Boost library?

For more information about Boost Formal Review Process, see:
http://www.boost.org/community/reviews.html

Thank you very much for your time and efforts.

--charley