The stdlib implementations of associative containers have serious drawbacks. At the very least, most projects should consider adopting absl::flat_hash_(set|map) and absl::btree_(set|map) (or similar replacements) over the stdlib containers.

I am also partial to explicit error handling over exceptions, and there is a lot to like about absl::Status (and absl::StatusOr).

Disclaimer: I work for Google but the views expressed are my own and don't necessarily reflect those of my employer.