Mailing list review 22-02-2021 - 29-03-2021

• Address that this is in fact not a pure library change and might require compiler support and approval from CWG - EWG
• to_address is only valid on contiguous iterator, while these algorithms support forward iterators
• explain in the paper why we can't use construct_at
• Try to gather feedback from more implementers

Guidance: Update the paper for a future presentation in a LEWG meeting

Will provide a new revision with the review comments addressed.

Thanks for looking into this!

P2283R1 constexpr for specialized memory algorithms (Michael Schellenberger Costa)

Sending this back to mailing list review. I'm thinking this can be seen again by the mailing list, then proceed to electronic poll.

A Library Evolution motion was made to advance this paper directly to electronic polling on 2021-11-24.

Motion failed

Motion failed.
The author informed me they are unlikely to be able to produce a new revision for c++23.

Comments from the mailing list

Going through construct_at prevents guaranteed copy elision for
uninitialized_copy/move* when the source is a range of prvalues; this
needs to be properly analyzed and addressed in the paper.
From a quick look, for the algorithms in namespace ranges, this
appears to be just a pessimization (they are constrained with
constructible_from, so the construction is required to be well-formed
even with intermediate materialization). For std::uninitialized_copy*,
this looks like a breaking change. std::uninitialized_move* appears to
be unaffected.

P2283R2 constexpr for specialized memory algorithms (Michael Schellenberger Costa)

P2283R2: constexpr for specialized memory algorithms

P2283R2: constexpr for specialized memory algorithms

2022-06-14 Library Evolution Telecon Minutes

Chair: Ben Craig

Minute Taker: Inbal Levi

Champion: Michael Schellenberger Costa

Summary

POLL: Send P2283R2 (constexpr for specialized memory algorithms) to LWG for C++26 classified as B3 (to be confirmed with a Library Evolution electronic poll).

Attendance: 18

# of Authors: 1

Author Position: WF

Outcome: Consensus

Next Steps

Await the outcome of the next electronic poll, then respond to LWG feedback as needed.

2022-07 Library Evolution Electronic Poll Outcomes

Poll 2.4: Send [P2283R2] constexpr Specialized Memory Algorithms to Library Working Group for C++26, classified as an improvement of an existing feature ([P0592R4] bucket 2 item).

Outcome: Unanimous consensus in favor.