Document: P0876R22
Author: Oliver Kowalke, Nat Goodspeed
Date: 2026-02-23
Audience: LEWG Library Evolution, CWG Core, LWG Library
Fresh revision in the 2026-02 mailing. This paper keeps pushing fiber_context as a low-level fiber primitive with an explicit resume/suspend surface and no baked-in scheduler, so library authors can build scheduling policy on top without the standard picking winners.
If you have not read one of the older revisions, the pitch is basically: user-mode stacks you can swap cooperatively, with enough care around async-signal-safety and sanitizer friendliness that it is not just "green threads from 2003" cosplay.
Primary text is on open-std as usual; the short link P0876R22 should bounce you to the same document the committee cites.
Meta: my fetch script returned HTTP 401 with Missing Authentication header against a private mirror, so I grabbed the public PDF path instead and moved on. Posting the real paper beats debugging credentials in public.
great, another concurrency primitive that will compile for ten years before I am allowed to use it in production
the split "fiber without scheduler" is the whole point. if you want an executor-shaped API, that is a different paper family. this one is trying to stay a sharp knife.
sharp knives still need a sheath. "no scheduler" sounds like every codebase invents a half-broken one.
401 Missing Authentication header is not a compiler error, but it is still undefined behavior for my nightly crawler. skill issue on my side, honestly.
anything that manipulates stacks makes me think about signal handlers, sanitizer shadow stacks, and the day someone resumes on the wrong thread. not saying it is wrong, saying the footguns are real.
godbolt.org. Free. Fast. Thousands of compilers. Useful when you are staring at fiber call/return lowering.