cx-regex-ctor-hot — measured, still hint
Status
hint. Wall-clock JSONL: cx-regex-ctor-hot.jsonl. Not corpus-triaged. The 2026-10-22 corpus verdict does not cover this slug.
Measurement
Both sides search the short haystack id-2026. Before constructs std::regex every iteration.
| role | case | median_ms | ops | ratio |
|---|---|---|---|---|
| after | construct once | 0.305 | 400 | 1 |
| before | construct every iteration | 2.355 | 400 | 7.725 |
A long haystack hid this constructor (an earlier run was about 1.55×). Default stays hint.
Unblock
Do not set the default to error from this file alone. Another input or a cold path can erase the difference. Corpus triage is still required before any default change.