alamb commented on code in PR #7922: URL: https://github.com/apache/arrow-rs/pull/7922#discussion_r2208285575
########## parquet-variant/src/builder.rs: ########## @@ -402,6 +402,11 @@ impl<S: AsRef<str>> FromIterator<S> for MetadataBuilder { impl<S: AsRef<str>> Extend<S> for MetadataBuilder { fn extend<T: IntoIterator<Item = S>>(&mut self, iter: T) { + let iter = iter.into_iter(); + let (min, max) = iter.size_hint(); + + self.field_names.reserve(max.unwrap_or(min)); + for field_name in iter { self.upsert_field_name(field_name.as_ref()); Review Comment: Ah, good call -- using lower bound sounds good -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: github-unsubscr...@arrow.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org