P5000R0 — Direction for ISO C++29

P5000R0 — Direction for ISO C++29 (9 items) All WG21

J. Garland, P. McKenney, R. Orr, B. Stroustrup, D. Vandevoorde, M. Wong

This paper proposes specific goals and priorities for the C++29 standardization cycle. It establishes safety (particularly via the Profiles framework) as the top priority, designates C++29 as a maintenance release to reduce friction from C++26's major features, and carries over pattern matching and networking as high-priority work. It also provides recommended procedural guidelines for committee chairs and members regarding proposal convergence and AI authorship.

Section 4 (Tier 2), subsections — Subsections under Section 4 are misnumbered 3.2 and 3.3 (belonging to Section 3); should be 4.1 and 4.2. [1]
Section 2.2 (Library Facilities) — "providing safe APIs..." is a sentence fragment — participial phrase with no main clause or finite verb. [2]
Section 2.2 (Library Facilities) — "assisting users to write type safe APIs not subject to legacy conversion rules" is a sentence fragment — participial phrase with no finite verb. [1] [3]
Document header vs. title line — Title is inconsistent between header and title line in plurality ("Direction" vs. "Directions") and spacing ("C++29" vs. "C++ 29"). [4]
Document header and Revision History — Document date (2026-02-18) contradicts stated publication date (2026-02-23). [5]
Section 1 (Abstract) vs. Section 6 — Paper number casing is inconsistent: "P3970R0" in the abstract vs. "P3970r0" in Section 6. [6]
Section 1 (Abstract) — Double comma (", ,") between the P3970R0 reference and "proposal convergence." [7]
Section 6, first bullet — Missing space: "cycleis" should be "cycle is". [8]

References — Anthropic Citations API

[1]
"Tier 2: Carry Over Priorities from C++26" followed by "3.2. Pattern Matching" and "3.3. Networking"

[2]
"These include strict mandates on safety P3970R0: Profiles and Safety: a call to action, , proposal convergence (P4024R0), and committee governance regarding AI (P4023R0)."

[3]
"A suggested roadmap for this cycleis detailed in the standalone paper"

[4]
"Header states "Date: 2026-02-18", while the revision history states "R0: this paper (2026-02-23 published)"."

[5]
"The title line reads "DIRECTION FOR ISO C++29" (singular, no space before "29"), while the running header reads "Directions for ISO C++ 29" (plural, with space before "29")."

[6]
"The abstract references "P3970R0: Profiles and Safety: a call to action", while Section 6 references "P3970r0: Profiles and Safety: a call to action"."

[7]
"In addition, providing safe APIs to replace those reliant on unsafe practices - such as pointer returns that can lead to use after free and other memory errors."

[8] chars 2271–2369
"Furthermore, assisting users to write type safe APIs not subject to legacy conversion rules. "

Summary: P5000R0 sets out the committee's priority tiers and recommended action guidelines for the C++29 cycle, organizing work into maintenance items, carry-over features from C++26 (pattern matching, networking), and new priorities (safety, library hardening, reflection-based facilities). Eight editorial and structural defects were found.

Pipeline: Discovery (Anthropic Opus + Citations API) → Verification Gate (OpenRouter Opus) → Report Writer (OpenRouter Opus)
Provenance: All references are machine-verified character positions from the Anthropic Citations API — deterministic, exact substrings, not model-generated quotes.