What sorting algorithm is used in the sort function?

In the C++ standard library (STL), the std::sort function typically uses a combination of algorithms known as IntroSort.

IntroSort is a hybrid sorting algorithm that combines:

• QuickSort for overall performance on average cases.
• Heapsort to guarantee worst-case performance (unlike QuickSort, which can degrade to O(n²)).
• InsertionSort for small data segments, where it is more efficient.

This combination provides good average speed (close to QuickSort) and guaranteed worst-case complexity of O(n log n), as well as efficiency for small arrays.

The specific implementation may vary slightly between compilers (e.g., GCC, Clang, MSVC), but the concept of IntroSort remains the standard for std::sort.