Modern C++ offers elegant abstractions like std::ranges that promise cleaner, more expressive code without sacrificing speed. Yet, as with many abstractions, real-world performance can tell a more nuanced story—one that every engineer should verify through careful benchmarking.

std::ranges may not deliver the performance that you expect

by Daniel Lemire

From the article:

Good engineers seek software code that is ‘simple’ in the sense that we can read and understand it quickly. But they they also look for highly performant code.

For the last 20 years, we have been offering programmers the possibility to replace conventional for loops with a more functional approach. To illustrate, suppose that you want to extract all even integers from a container and create a new container. In conventional C++, you would proceed with a loop, as follows.

std::vector<int> even_numbers;
for (int n : numbers) {
 if (n % 2 == 0) {
 even_numbers.push_back(n);
 }
}