Vector and []-operator overloading

Question

I have inherited my class from std::vector. Now I want to overload the []-operator.
When I try to assign a new value to my vector, e.g. v[0]=5, I should rec

Answer 1

The code below illustrates how to call the operator[] from the vector base class....

#include 
#include 

struct Vec : std::vector
{
    int& operator[](int n)
    {
        std::cout << "operator[](" << n << ")\n";
        return std::vector::operator[](n);
    }
};

int main()
{
    Vec v;
    v.push_back(10);
    v.push_back(20);
    v[0] += 5;
    std::cout << v[0] << ' ' << v[1] << '\n';
}

Output when I run it:

operator[](0)
operator[](1)
operator[](0)
15 20

Don't take all this talk about "do not inherit from std::vector" too seriously: you have to go out of your way to delete a dynamically allocated Vec using a std::vector*, or do an accidental by-value slicing copy - and even then it'd probably only bite you if you had added data members. You should make sure you understand those risks then make your own assessment, but for small utility programs etc. it's productive to inherit from such classes sometimes....