const T& front() const;
#includeIn this example, we create a set of integers called mySet with the elements {5, 10, 15, 20}. We then use the Set front function to retrieve the first element of the set, which is 5, and print it to the console. We demonstrate that attempting to modify the front element directly will result in a compile error, but we can modify it indirectly by inserting a new element at the beginning of the set. This code uses the STL library, which is included as part of the C++ standard library.#include int main() { std::set mySet = {5, 10, 15, 20}; // Get the first element of the set using front() std::cout << "The first element of mySet is " << mySet.front() << std::endl; // Attempting to modify the first element using front() directly will result in a compile error // mySet.front() = 25; // However, we can modify the first element indirectly by inserting a new element at the beginning mySet.insert(2); std::cout << "The new first element of mySet is " << mySet.front() << std::endl; return 0; }