scovich commented on code in PR #7922: URL: https://github.com/apache/arrow-rs/pull/7922#discussion_r2205958233
########## 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: The upper bound of the size hint is allowed to be `usize::MAX`. We probably shouldn't try to reserve that many field names? -- 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