P3014 R0 Customizing std::expected's exception

[wg21bot]

P3014R0 Customizing std::expected's exception (Jonathan Müller)

[billy-baker]

Library Evolution Meeting Kona 2023-11-09

P3014R0: Customizing std::expected's exception

2023-11-09 Library Evolution Kona 2023 Meeting Minutes

Chair: Billy Baker / Nevin Liber
Champion: Jonathan Muller
Minute Taker: Ben Craig

Polls

POLL: std::expected_traits should be provided rather than the alternative design (unexpected_exception - workaround for third template parameter).

Strongly Favor	Weakly Favor	Neutral	Weakly Against	Strongly Against
1	5	3	2	1

Attendance: 27 + 5

# of Authors: 1

Author Position: WF

Outcome: There is a preference for expected_traits but there is also a limited set of responses.

POLL: Given that our time is limited, a marker/static type/tag dispatch (not tied to exception, not reopening std namespace) approach should be explored.

Strongly Favor	Weakly Favor	Neutral	Weakly Against	Strongly Against
2	7	5	1	1

Attendance: 29 + 5

# of Authors: 1

Author Position: N

Outcome: There is a preference to explore.

POLL: Given that our time is limited, we should solve the problem of customizing the unexpected exception.

Strongly Favor	Weakly Favor	Neutral	Weakly Against	Strongly Against
4	3	5	4	2

Attendance: 29 + 5

# of Authors: 1

Author Position: N

Outcome: No consensus

SA: could be swayed if there was a new member function rather than changing the semantics of existing functions.

Summary

Note that this problem was not viewed as a high-priority issue, but there's a preference to explore the marker/static type/tag dispatch approach. The author may come back with an updated proposal exploring this design space.