What is the difference between std::equal_range and std::lower_bound?

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**equal_range** — returns both bounds. **lower_bound** — returns only lower bound. ```cpp std::vector v = {1, 2, 2, 2, 3, 4}; // lower_bound — just first >= value auto lb = std::lower_bound(v.begin(), v.end(), 2); // equal_range — both bounds auto range = std::equal_range(v.begin(), v.end(), 2); auto lb = range.first; // Same as lower_bound auto ub = range.second; // Same as upper_bound // Count int count = std::distance(range.first, range.second); // 3 ``` **equal_range is convenience:** - Single call instead of two. - More efficient (single search). - Returns std::pair.

C++: What is the difference between std::equal_range and std::lower_bound?