#news
13 posts tagged #news.
-
simdjson meets reflection: sb << my_struct at 6.8 GB/s
simdjson now ships a C++26 reflection backend: define SIMDJSON_STATIC_REFLECTION, and sb << my_struct serializes any aggregate at SIMD speed. The CITM Catalog benchmark hits 6.8 GB/s. Combined with P3394 annotations for rename/skip, this is the production JSON path the reflection series has been building toward.
-
The hidden cost of <meta> -- and the three-line fix
Vittorio Romeo measured what C++26 reflection actually costs: the <meta> header adds ~181ms per TU on GCC 16.1, but the reflection algorithm itself is ~0.07ms per enumerator. The header is 2500x more expensive than the logic. A three-line CMake PCH stanza cuts the header cost by 2.3x. Modules, surprisingly, make it worse.
-
The May 2026 WG21 mailing in five papers (pre-Brno, 116 total)
WG21 dropped the pre-Brno mailing in early May -- 116 papers, the largest pre-meeting mailing since the C++20 design crunch. Five papers are doing the heavy lifting for C++29's safety story (the headline axis named in P5000R1 'Direction for ISO C++29'), plus the coroutines-for-I/O work that finally got first LEWG review on the schedule. This is the table of contents for what wro.cpp will be tracking through to Brno (8-13 June).
-
C++ Safety State of the Union: May 2026
C++ in May 2026 has four conversations running at once: regulators (CISA, EU CRA) demanding memory-safety roadmaps; the committee fighting over how to respond (Hagenberg vote 19 profiles / 9 Safe C++ / 11 both); what actually shipped in C++26 (P2900 contracts, P3471 hardened stdlib, P2996 reflection); and what the industry actually deployed (Chrome MiraclePtr -57% UAF, Google's 0.3% perf-cost data, Apple libc++ safe-buffers). They don't talk to each other in public. This essay wires them. Pre-Brno (8-13 June) reading.
-
Revzin at C++Now: 'Reflection Is Only Half the Story' -- what generation looks like next
Barry Revzin's C++Now 2026 keynote (Mon 4 May, Aspen) landed the line the C++ reflection community has been circling for two years: C++26 reflection lets you OBSERVE -- the next question is what it looks like to GENERATE. The 90-minute talk is a tour of source-code-generation design space (macros, templates, Rust proc-macros, Swift macros, D mixins) and reads as the natural sequel to wro.cpp's whole 'Where this is heading' triptych framing.
-
What reinterpret_cast doesn't do: Fertig on std::start_lifetime_as and the C++23 escape hatch
Andreas Fertig's 2026-05-18 post (re-shared on isocpp.org) makes a pointed case: reinterpret_cast and std::start_lifetime_as look interchangeable -- but only if you don't read the abstract-machine fine print. reinterpret_cast is a POINTER operation; std::start_lifetime_as is an OBJECT-LIFETIME operation. The 5-line difference between UB-then-it-works-on-my-compiler and defined-behavior.
-
Sutter's BeCPP keynote: C++ added more developers in 4 years than any other language
Herb Sutter's keynote at the BeCPP Symposium 2026 (March 30, Howest, Belgium) opened with a SlashData chart almost nobody outside the room has seen yet: C++ developer population grew 72% from Q1 2022 to Q1 2025 -- from 9.5M to 16.3M. That is the biggest absolute net gain of any general-purpose language over the period. Rust grew faster in percentage (137%) but on a smaller base (5.1M total). Here is the chart, the numbers behind it, and the thesis Sutter built on top -- plus an honest read on what 'fastest growing' means when JavaScript is still bigger than the second + third place combined.
-
The five most useful things C++26 reflection unlocks (in effort order)
C++26 reflection looks like it requires a PhD in template metaprogramming. It does not. Five concrete projects you can build with it, ranked from five minutes to weeks -- use this as a triage when picking your first reflection-powered project.
-
Is std::vector consteval or constexpr? A reader's question, answered
A colleague asked: 'Is std::vector consteval and not constexpr?' Short answer: no, but the intuition is right. Long answer: the constexpr/consteval/constinit trio, the transient-allocation rule, and why std::define_static_array exists.
-
Reflection in the wild: April 2026 in five links
Five things happened to C++26 reflection in April 2026 -- GCC 16.1, Glaze v7.2, a Revzin write-up, a Lemire/Thiesen JSON talk, and one honest list of what is still not shipping.
-
Glaze v7.2 vs your hand-rolled JSON: a 30-line benchmark
Glaze v7.2 ships a P2996 backend that retires __PRETTY_FUNCTION__, lifts the 128-member cap, and serializes private members. Here is when you still write your own thirty lines -- and when one call wins.
-
GCC 16.1 ships C++26 reflection -- your 30-line hands-on
GCC 16.1 dropped on 30 April 2026 with -freflection. C++26 was finalized at Croydon five weeks earlier. Here is a 25-line program you can compile and run today on your laptop.
-
C++26 is done -- five weeks since Croydon, here's what shipped
Five weeks ago WG21 voted C++26 to publication in Croydon. The dust has settled enough to take stock of what landed, what compiles today, and what it means for the wro.cpp reflection series.