P2587 to_string or not to_string

[wg21bot]

P2587R0 to_string or not to_string (Victor Zverovich)

[brycelelbach]

2022-06-28 Library Evolution Telecon

P2587R1: to_string or not to_string

2022-06-28 Library Evolution Telecon Minutes

Chair: Bryce Adelstein Lelbach

Minute Taker: Ben Craig

Champion: Victor Zverovich

Start: 2022-06-28 11:16 Eastern

Does this paper have:

• Examples?
  • Yes.
• Field experience?
  • Implementation experience?
    • Yes, in fmt.
  • Deployment experience?
    • Some research was done on the impact on existing code.
• Performance considerations?
  • Yes.
• Wording?
  • Yes.
• Feature test macro?
  • No, but one will be added.

POLL: Fix to_string as proposed by P2587R1 (to_string or not to_string).

Strongly Favor	Weakly Favor	Neutral	Weakly Against	Strongly Against
4	9	4	2	1

Attendance: 26

# of Authors: 1

Author Position: SF

Outcome: Weak consensus in favor.

SA: Breaks compatibility.

POLL: Deprecate all to_string overloads.

Strongly Favor	Weakly Favor	Neutral	Weakly Against	Strongly Against
1	9	2	9	1

Attendance: 26

# of Authors: 1

Author Position: WA

Outcome: No consensus.

POLL: Deprecate to_string floating point overloads.

Strongly Favor	Weakly Favor	Neutral	Weakly Against	Strongly Against
2	8	6	4	2

Attendance: 26

# of Authors: 1

Author Position: WA.

Outcome: No consensus.

WA: This is a lot of design on the fly.

End: 11:43

Summary

This paper aims to fix issues with to_string, in particular how it works (or doesn't) for floating point types.
Library Evolution was generally supportive of the direction of the paper, but there was concern about the impact the proposed fixes would have on existing code.
There were also some questions about how to word the proposed fixes to ensure they can be backported.

Next Steps

Revise the paper and return to Library Evolution for further design review:

• Further explore the impact this change will have on existing code.
• Consider adding to_string overloads for anything that's formattable.