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Update len-metamethod-rawlen.md

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Arseny Kapoulkine 2022-06-13 11:31:42 -07:00 • committed by GitHub
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@ -35,6 +35,8 @@ and even when it is, using the existing metamethod-absence-caching approach we u
statistically significant difference on existing benchmark suite. This does complicate the `#` computation a little more which may affect JIT as well, but even if the
table doesn't have a metatable the process of computing `#` involves a series of condition checks and as such will likely require slow paths anyway.
This is technically changing semantics of `#` when called on tables with an existing `__len` metamethod, and as such has a potential to change behavior of an existing valid program. That said, it's unlikely that any table would have a metatable with `__len` metamethod as outside of userdata these do not do anything.
## Alternatives
Do not implement `__len`.