Description : The list::vector() is a built-in function in C++ STL which is used to find the number of elements present in a vector container.
Example:
// Creating a vector
std::vector<int> example;
// Adding elements to the vector
example.push_back(10);
example.push_back(20);
example.push_back(30);
example.push_back(40);
// getting size of the list
int size = example.size();
std::cout << "The vector contains " << size << " elements";