Operator[][] overload

Question

Is it possible to overload [] operator twice? To allow, something like this: function[3][3](like in a two dimensional array).

If it is pos

Answer 1

With a std::vector>, you can build the inside vector using custom input operator that iterate over your data and return a pointer to each data.

For example:

size_t w, h;
int* myData = retrieveData(&w, &h);

std::vector > data;
data.reserve(w);

template
struct myIterator : public std::iterator
{
    myIterator(T* data) :
      _data(data)
    {}
    T* _data;

    bool operator==(const myIterator& rhs){return rhs.data == data;}
    bool operator!=(const myIterator& rhs){return rhs.data != data;}
    T* operator*(){return data;}
    T* operator->(){return data;}

    myIterator& operator++(){data = &data[1]; return *this; }
};

for (size_t i = 0; i < w; ++i)
{
    data.push_back(std::vector(myIterator(&myData[i * h]),
        myIterator(&myData[(i + 1) * h])));
}

Live example

This solution has the advantage of providing you with a real STL container, so you can use special for loops, STL algorithms, and so on.

for (size_t i = 0; i < w; ++i)
  for (size_t j = 0; j < h; ++j)
    std::cout << *data[i][j] << std::endl;

However, it does create vectors of pointers, so if you're using small datastructures such as this one you can directly copy the content inside the array.