cs-list-add-no-capacity — List.Add without Capacity
Status: measured
Claim
new List<int>() then Add N times is about 1.31× new List<int>(N) on .NET 10.0.13. An earlier busy-machine pair was about 1.25×. Two later runs on the same host were about 1.72× (0.462 ms vs 0.269 ms, and 0.426 ms vs 0.248 ms); the no-capacity samples spread from about 0.30 ms to 0.90 ms, so those runs do not replace the row below. The old ~13× figure is not this run. The rule stays off.
How measured
-
Harness:
examples/bench/EvidenceCsBench(dotnet run -c Release) -
N=200000
-
Raw lines:
cs-list-add-no-capacity.jsonl
Runtime (this evidence file)
| Field | Value |
|---|---|
| When | 2026-10-23 UTC (linux x64, load 0.58) |
| dotnet | 10.0.13 |
Median before (list_add_nocap) | 0.4057 ms |
Median after (list_capacity) | 0.3101 ms |
| ratio before/after | ~1.31× |
Lint mapping
csharpperf-lint cs-list-add-no-capacity: keep default severity.
Limits
- Default stays off (G3).