Question

I seem to be seeing more ‘for’ loops over iterators in questions & answers here than I do for_each(), transform(), and the like. Scott Meyers suggests that stl algorithms are preferred, or at least he did in 2001. Of course, using them often means moving the loop body into a function or function object. Some may feel this is an unacceptable complication, while others may feel it better breaks down the problem.

So… should STL algorithms be preferred over hand-rolled loops?

Answer 1

It depends on:

• Whether high-performance is required
• The readability of the loop
• Whether the algorithm is complex

If the loop isn’t the bottleneck, and the algorithm is simple (like for_each), then for the current C++ standard, I’d prefer a hand-rolled loop for readability. (Locality of logic is key.)

However, now that C++0x/C++11 is supported by some major compilers, I’d say use STL algorithms because they now allow lambda expressions — and thus the locality of the logic.