How do I erase an element from std::vector<> by index?

std::vector<int> vec;



vec.push_back(6);

vec.push_back(-17);

vec.push_back(12);



// Deletes the second element (vec[1])

vec.erase(std::next(vec.begin()));

// Deletes the second through third elements (vec[1], vec[2])

vec.erase(std::next(vec.begin(), 1), std::next(vec.begin(), 3));

vector.erase( vector.begin() + 3 ); // Deleting the fourth element

vector.erase( vector.begin() + 3, vector.begin() + 5 ); // Deleting from fourth element to sixth element