Subtype checking micro-optimization by JukkaL · Pull Request #19384 · python/mypy

@JukkaL

Speeds up self-check by about 0.6%. The assertion is very hot, and
the original version always created a set, which is slow.

JelleZijlstra

hauntsaninja

JukkaL added a commit that referenced this pull request

Jul 16, 2025

@JukkaL