Billion-query-per-second lookup tables in C++
Comments on “Billion-query-per-second lookup tables in C++”
3 judges. Scored by all three judges. Only the day’s top stories get the claim check. How far stories are checked
A new C++23 header-only library, perfect_hash, builds compile-time perfect hash maps for keys known in advance, such as HTTP methods or keywords. Using gperf-style association tables and 16-byte vector key comparison, it reports lookups around 1.2 to 2 ns on an Apple M3 Max, roughly 3 to 13 times faster…
Why it ranked
No. 49 of 124 with a score of 0.62. The panel rated it highest on technical depth (0.89) and new information (0.88), lowest on significance (0.48).
Every answer behind this is in the table under Score.
Score
0.62total under rubric v2.2
- Significance0.48
- Reader interest0.76
- Audience breadth0.52
- Practical relevance0.78
- Substantiated0.80
- Technical depth0.89
- New information0.88
- Counts against: Promotional0.14
- Counts against: Overclaim0.32
Each judge’s answer per question (0–1), their mean and spread, and what the question adds to the score (weight × mean).
| Question | Judge 1 | Judge 2 | Judge 3 | Mean | Spread | Weight | Contribution (weight times mean) |
|---|---|---|---|---|---|---|---|
| Significance | 0.54 | 0.30 | 0.62 | 0.48 | 0.32 | +0.24 | +0.116 |
| Reader interest | 0.69 | 0.70 | 0.90 | 0.76 | 0.21 | +0.26 | +0.198 |
| Audience breadth | 0.57 | 0.40 | 0.58 | 0.52 | 0.18 | +0.13 | +0.067 |
| Practical relevance | 0.83 | 0.72 | 0.80 | 0.78 | 0.11 | +0.22 | +0.172 |
| Substantiated | 0.84 | 0.70 | 0.86 | 0.80 | 0.16 | +0.05 | +0.040 |
| Technical depth | 0.96 | 0.85 | 0.87 | 0.89 | 0.11 | +0.05 | +0.045 |
| New information | 0.90 | 0.80 | 0.93 | 0.88 | 0.13 | +0.05 | +0.044 |
| Promotional | 0.10 | 0.15 | 0.18 | 0.14 | 0.08 | −0.19 | −0.027 |
| Overclaim | 0.47 | 0.20 | 0.28 | 0.32 | 0.27 | −0.11 | −0.035 |
| Sum of contributions | +0.621 | ||||||
| Claim-check penalty | 0.000 | ||||||
| Total, as published | 0.621 | ||||||
Spread is the highest minus the lowest judge answer. marks a spread above 0.40: the judges disagree, and the story is marked contested.
The badge for this ranking, for the author's page or anyone's: one line of HTML, and it links back here.
<a href="https://rubric.hrih.si/editions/2026-10-27/49/"><img src="https://rubric.hrih.si/badge/2026-10-27/49.svg" alt="Ranked #49 on Rubric, 27 Oct 2026" width="245" height="28"></a>Also covered by
No other coverage was clustered with this story.
Elsewhere
Elsewhere: HN 3 pts, not on front page
Recorded for context only, checked 27 Oct 2026, 05:46 UTC. It played no part in the ranking.