People keep asking how to traverse tbb::concurrent_hash_map concurrently with other operations. But it wouldn’t be worth the blog if there was not any problem. The Reference clearly states that:

Concurrent operations (count, find, insert, and erase) invalidate any existing iterators that point into the table, An exception to this rule is that count and find do not invalidate iterators if no insertions or erasures have occurred after the most recent call to method rehash.