Should one prefer STL algorithms over hand-rolled loops?

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 algori

Answer 1

The for loop is imperative, the algorithms are declarative. When you write std::max_element, it’s obvious what you need, when you use a loop to achieve the same, it’s not necessarily so.

Algorithms also can have a slight performance edge. For example, when traversing an std::deque, a specialized algorithm can avoid checking redundantly whether a given increment moves the pointer over a chunk boundary.

However, complicated functor expressions quickly render algorithm invocations unreadable. If an explicit loop is more readable, use it. If an algorithm call can be expressed without ten-storey bind expressions, by all means prefer it. Readability is more important than performance here, because this kind of optimization is what Knuth so famously attributes to Hoare; you’ll be able to use another construct without trouble once you realize it’s a bottleneck.