What is the performance of std::multimap in C++11?

Can you explain the performance characteristics of std::multimap in C++11?

Sure! The std::multimap in C++11 is implemented as a balanced binary tree, typically a Red-Black tree. This allows for logarithmic time complexity for insertions, deletions, and lookups.

How does it compare to std::map in terms of performance?

The main difference is that std::multimap allows duplicate keys, while std::map does not. Performance-wise, both have similar time complexities, but std::multimap may have slightly more overhead due to managing duplicates.

Are there any scenarios where std::multimap would be preferred over std::map?

Yes, if you need to store multiple values for the same key, std::multimap is the better choice. It's ideal for scenarios like counting occurrences or grouping data.

What about memory usage? Is std::multimap more memory-intensive?

Yes, std::multimap can be more memory-intensive than std::map due to the additional pointers required to manage duplicate keys and the structure of the tree.