Here is an example of a C++ threading code that demonstrates how to use multiple threads and synchronize them using condition variable. This is basic producer-consumer scenario of how Apache Kafka streams data.
std::for_each, std::ranges::for_each, std::optional, and std::execution::par_unseq are features from C++20 and C++23 that helps efficiently loop through the loop, loop in parallel, add optional values in the data structure of your choice, etc.
std::any_of, std::none_of and std::all_of is a C++20 feature that helps efficiently check for basic conditions in the data structures. This is very optimal because of early termination once some fact is found and the algorithm don’t have to iterate more to further prove anything before returning the result.