What are the differences between std::map and std::unordered_map in C++17?

Can you explain the differences between std::map and std::unordered_map in C++17?

Sure! The main difference is that std::map is ordered and uses a binary search tree, while std::unordered_map is unordered and uses a hash table.

What are the performance implications of using one over the other?

std::map has O(log n) complexity for insertions and lookups, while std::unordered_map has average O(1) complexity, making it faster for large datasets.

Are there any scenarios where I should prefer std::map over std::unordered_map?

Yes, if you need to maintain order or require sorted keys, std::map is the better choice. It's also useful for range queries.

Can you give an example of when to use std::unordered_map?

Certainly! Use std::unordered_map when you need fast access to elements and don't care about the order, like counting occurrences of items.