How do I avoid rehashing overhead with std::set in performance-sensitive code?

When working with performance-sensitive code in C++, using a data structure like std::set can introduce overhead due to rehashing, especially when the number of elements grows unpredictably. To minimize this impact, consider the following strategies:

• Reserve Space: Use std::set::insert method judiciously and ensure your data structure is pre-allocated for expected sizes, if possible.
• Choose Appropriate Types: Leverage types and compare functions that are efficient in terms of comparison and memory usage.
• Batch Inserts: When adding multiple elements, try to insert them in bulk if possible, as this can reduce the number of rehashing operations.

Using these strategies can help you manage the performance overhead related to std::set in critical code paths.