byte_coder52 · 09.05.2026

What are the advantages of std::distance over subtracting iterators in C++?

Hello colleagues! I recently started learning C++ and encountered an interesting point when working with iterators. Suppose I have std::vector v = {10, 20, 30, 40, 50}; and I want to find the distance between two iterators, for example, from the beginning to the middle. I know that for random access iterators (like those of vector), you can simply subtract one iterator from another: auto mid = v.begin() + 2; ptrdiff_t dist = mid - v.begin(); // dist = 2. This works and seems very simple. But in other developers' code, I often see the use of std::distance: auto dist = std::distance(v.begin(), mid);. And I don't understand why use a function if you can just subtract? After all, subtraction is shorter and probably faster? I understand that std::distance is a template function from the header. But

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