P0829 Freestanding Proposal

[jensmaurer]

P0829R4 Freestanding Proposal (Ben Craig)

[brycelelbach]

Discussed at the Kona 2019 meeting by LEWGI

Champion: Ben Craig

Minute Taker: Jeffrey Yasskin

Start Overview: 13:24

Start Review: 13:29

Formalizing -fno-exceptions would mean we wouldn’t have to cut out members.

Should new std:: classes/class methods/functions be opt-in or opt-out?

Start Polling: 14:01

We will poll some options and see what has the strongest consensus.

POLL: Allow standard library classes (for example: array, string_view, optional, bitset, variant) to not have some members in freestanding mode (e.g. might not be declared in freestanding).

Strongly For	Weakly For	Neutral	Weakly Against	Strongly Against
5	3	4	3	0

Attendance: 17

That has weak consensus.

POLL: Allow standard library classes (for example: array, string_view, optional, bitset, variant) to have some methods that have implementation-defined behavior in freestanding.

Strongly For	Weakly For	Neutral	Weakly Against	Strongly Against
1	4	5	4	1

Attendance: 17

That's not consensus.

Steve (A): Don’t want changes in behavior going between hosted vs freestanding.

Rene (A): Don’t like implementation-defined behavior.

POLL: Library functions may terminate instead of throwing in freestanding.

Strongly For	Weakly For	Neutral	Weakly Against	Strongly Against
0	7	9	0	0

Attendance: 17

That has consensus.

POLL: Allow standard library classes (for example: array, string_view, optional, bitset, variant) to have some members declared but not defined in freestanding.

Strongly For	Weakly For	Neutral	Weakly Against	Strongly Against
3	8	4	0	0

Attendance: 18

That has the strongest consensus of all the options we've polled.

End: 14:15

CONSENSUS: Bring a revision of P0829R4, with the guidance below, to LEWG(I) for further design review.

• Explore allowing standard library classes to have some members declared but not defined in freestanding.

[brycelelbach]

This should just go to LEWG when revised.

[ben-craig]

This specific paper number is dead. Parts of the paper are going into other papers, with P1642 and P2198 being the pieces that are currently outstanding. Closing.