Is it faster to iterate an std::vector by references to elements or by index?

Asked Jun 28 '22 at 05:33

Active Jun 28 '22 at 05:38

Viewed 71 times

Let v be a std::vector<int>. Which of the two methods below is faster for iterating over its elements?

for (auto& el: v) {...el...} or for (size_t i = 0; i < v.size(); ++i) {...v[i]...}

I'm seeing the former in a lot of competitive programming solutions, however I don't get how it can be faster than the one below unless the vector objects are something different from a built-in type

edited Jun 28 '22 at 05:37

asked Jun 28 '22 at 05:33

A. Fenzry

1

Unrelated, "competitive coding solutions" is an oxymoron. – WhozCraig Jun 28 '22 at 05:35
Akso, depending on the implementation. The range-for is easier to read and has one less identifier. – DevSolar Jun 28 '22 at 05:38

Is it faster to iterate an std::vector by references to elements or by index?

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