--- title: 2025-10 Library Evolution Poll Outcomes document: P3873R0 date: 2026-01-16 audience: LEWG Library Evolution reply-to: - "Inbal Levi" - "Fabio Fracassi" - "Andreas Weis" - "Nevin Liber" - "Billy Baker" - "Corentin Jabot" paper-type: proposal --- --- ## Introduction In 2025-10, the C++ Library Evolution group conducted a series of electronic decision polls [[P3872R0]](https://wg21.link/P3872r0). This paper provides the results of those polls and summarizes the results. In total, 9 people participated in the polls. Thank you to everyone who participated, and to the papers' authors for all their hard work! ## Poll Outcomes - SF: Strongly Favor. WF: Weakly Favor. N: Neutral. WA: Weakly Against. SA: Strongly Against. | Poll SF WF N WA SA Outcome Poll 1: Send "[[P3774R1]](https://wg21.link/p3774r1) Rename std::nontype, and make it broadly useful" to Library Working Group as a DR (fix) for C++26. 3 5 0 0 1 Consensus in favor Poll 2: Send "[3798R1] The unexpected in std::expected" to Library Working Group for C++29. 6 2 0 0 0 Strong Consensus in favor | SF WF N WA SA Outcome Poll 1: Send "[[P3774R1]](https://wg21.link/p3774r1) Rename std::nontype, and make it broadly useful" to Library Working Group as a DR (fix) for C++26. 3 5 0 0 1 Consensus in favor Poll 2: Send "[3798R1] The unexpected in std::expected" to Library Working Group for C++29. 6 2 0 0 0 Strong Consensus in favor | WF N WA SA Outcome Poll 1: Send "[[P3774R1]](https://wg21.link/p3774r1) Rename std::nontype, and make it broadly useful" to Library Working Group as a DR (fix) for C++26. 3 5 0 0 1 Consensus in favor Poll 2: Send "[3798R1] The unexpected in std::expected" to Library Working Group for C++29. 6 2 0 0 0 Strong Consensus in favor | N WA SA Outcome Poll 1: Send "[[P3774R1]](https://wg21.link/p3774r1) Rename std::nontype, and make it broadly useful" to Library Working Group as a DR (fix) for C++26. 3 5 0 0 1 Consensus in favor Poll 2: Send "[3798R1] The unexpected in std::expected" to Library Working Group for C++29. 6 2 0 0 0 Strong Consensus in favor | WA SA Outcome Poll 1: Send "[[P3774R1]](https://wg21.link/p3774r1) Rename std::nontype, and make it broadly useful" to Library Working Group as a DR (fix) for C++26. 3 5 0 0 1 Consensus in favor Poll 2: Send "[3798R1] The unexpected in std::expected" to Library Working Group for C++29. 6 2 0 0 0 Strong Consensus in favor | SA Outcome Poll 1: Send "[[P3774R1]](https://wg21.link/p3774r1) Rename std::nontype, and make it broadly useful" to Library Working Group as a DR (fix) for C++26. 3 5 0 0 1 Consensus in favor Poll 2: Send "[3798R1] The unexpected in std::expected" to Library Working Group for C++29. 6 2 0 0 0 Strong Consensus in favor | Outcome Poll 1: Send "[[P3774R1]](https://wg21.link/p3774r1) Rename std::nontype, and make it broadly useful" to Library Working Group as a DR (fix) for C++26. 3 5 0 0 1 Consensus in favor Poll 2: Send "[3798R1] The unexpected in std::expected" to Library Working Group for C++29. 6 2 0 0 0 Strong Consensus in favor | Poll 1: Send "[[P3774R1]](https://wg21.link/p3774r1) Rename std::nontype, and make it broadly useful" to Library Working Group as a DR (fix) for C++26. 3 5 0 0 1 Consensus in favor Poll 2: Send "[3798R1] The unexpected in std::expected" to Library Working Group for C++29. 6 2 0 0 0 Strong Consensus in favor | 3 5 0 0 1 Consensus in favor Poll 2: Send "[3798R1] The unexpected in std::expected" to Library Working Group for C++29. 6 2 0 0 0 Strong Consensus in favor | 5 0 0 1 Consensus in favor Poll 2: Send "[3798R1] The unexpected in std::expected" to Library Working Group for C++29. 6 2 0 0 0 Strong Consensus in favor | 0 0 1 Consensus in favor Poll 2: Send "[3798R1] The unexpected in std::expected" to Library Working Group for C++29. 6 2 0 0 0 Strong Consensus in favor | 0 1 Consensus in favor Poll 2: Send "[3798R1] The unexpected in std::expected" to Library Working Group for C++29. 6 2 0 0 0 Strong Consensus in favor | 1 Consensus in favor Poll 2: Send "[3798R1] The unexpected in std::expected" to Library Working Group for C++29. 6 2 0 0 0 Strong Consensus in favor | Consensus in favor Poll 2: Send "[3798R1] The unexpected in std::expected" to Library Working Group for C++29. 6 2 0 0 0 Strong Consensus in favor | Poll 2: Send "[3798R1] The unexpected in std::expected" to Library Working Group for C++29. 6 2 0 0 0 Strong Consensus in favor | 6 2 0 0 0 Strong Consensus in favor | 2 0 0 0 Strong Consensus in favor | 0 0 0 Strong Consensus in favor | 0 0 Strong Consensus in favor | 0 Strong Consensus in favor | Strong Consensus in favor | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | Poll 1: Send "[[P3774R1]](https://wg21.link/p3774r1) Rename std::nontype, and make it broadly useful" to Library Working Group as a DR (fix) for C++26. 3 5 0 0 1 Consensus in favor Poll 2: Send "[3798R1] The unexpected in std::expected" to Library Working Group for C++29. 6 2 0 0 0 Strong Consensus in favor | 3 5 0 0 1 Consensus in favor Poll 2: Send "[3798R1] The unexpected in std::expected" to Library Working Group for C++29. 6 2 0 0 0 Strong Consensus in favor | 5 0 0 1 Consensus in favor Poll 2: Send "[3798R1] The unexpected in std::expected" to Library Working Group for C++29. 6 2 0 0 0 Strong Consensus in favor | 0 0 1 Consensus in favor Poll 2: Send "[3798R1] The unexpected in std::expected" to Library Working Group for C++29. 6 2 0 0 0 Strong Consensus in favor | 0 1 Consensus in favor Poll 2: Send "[3798R1] The unexpected in std::expected" to Library Working Group for C++29. 6 2 0 0 0 Strong Consensus in favor | 1 Consensus in favor Poll 2: Send "[3798R1] The unexpected in std::expected" to Library Working Group for C++29. 6 2 0 0 0 Strong Consensus in favor | Consensus in favor Poll 2: Send "[3798R1] The unexpected in std::expected" to Library Working Group for C++29. 6 2 0 0 0 Strong Consensus in favor | Poll 2: Send "[3798R1] The unexpected in std::expected" to Library Working Group for C++29. 6 2 0 0 0 Strong Consensus in favor | 6 2 0 0 0 Strong Consensus in favor | 2 0 0 0 Strong Consensus in favor | 0 0 0 Strong Consensus in favor | 0 0 Strong Consensus in favor | 0 Strong Consensus in favor | Strong Consensus in favor | | | | | | | | | Poll 2: Send "[3798R1] The unexpected in std::expected" to Library Working Group for C++29. 6 2 0 0 0 Strong Consensus in favor | 6 2 0 0 0 Strong Consensus in favor | 2 0 0 0 Strong Consensus in favor | 0 0 0 Strong Consensus in favor | 0 0 Strong Consensus in favor | 0 Strong Consensus in favor | Strong Consensus in favor | | | | | | | | | | | | | | | All the polls have consensus in favor and the papers will be forwarded to LWG. ## Selected Poll Comments For some of the comments, small parts were removed to anonymize. ### Poll 1: Send "[[P3774R1]](https://wg21.link/p3774r1) Rename std::nontype, and make it broadly useful" to Library Working Group as a DR (fix) for C++26. > I fully agree with this paper, the new names are a considerable improvement. > > — Strongly Favor > Getting away from "nontype" name is important. Choice of new name is not optimal but acceptable. > > — Weakly Favor > Positive names are better than negative names (things with not, non, etc.). > > — Weakly Favor > Reconsider R0 / P3843R0. > > — Strongly Against ### Poll 2: Send "[[P3798R1]](https://wg21.link/p3798r1) The unexpected in std::expected" to Library Working Group for C++29. > Seems very appropriate for reasons of symmetry. I looks much more like an oversight or defect, so I would also suggest it for C++26. > > — Strongly Favor > I’m all for more expressive code. Minimal interfaces are not easy to teach, to discover and to read. > > — Strongly Favor > This is a simple enough addition to improve usability. While I don’t see a strong need for this change, there is no reason not to do this. > > — Weakly Favor ## References ### Informative References **[P3774R1] Jan Schultke, Bronek Kozicki, Tomasz Kamiński. [Rename std::nontype, and make it broadly useful](https://wg21.link/p3774r1). 14 August 2025. URL: [https://wg21.link/p3774r1](https://wg21.link/p3774r1) [P3798R1] Alex Kremer, Ayaz Salikhov. [The unexpected in std::expected](https://wg21.link/p3798r1). 12 August 2025. URL: [https://wg21.link/p3798r1](https://wg21.link/p3798r1) [P3872R0] Inbal Levi; et al. [2025-10 Library Evolution Polls](https://wg21.link/P3872r0). 06 October 2025. URL: [https://wg21.link/P3872r0](https://wg21.link/P3872r0)**