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

It is possible to overload multiple [] using a specialized template handler. Just to show how it works :

#include 
#include 
#include 
#include 
#include 

using namespace std;

// the number '3' is the number of [] to overload (fixed at compile time)
struct TestClass : public SubscriptHandler {

    // the arguments will be packed in reverse order into a std::array of size 3
    // and the last [] will forward them to callSubscript()
    int callSubscript(array& v) {
        return accumulate(v.begin(),v.end(),0);
    }

};

int main() {


    TestClass a;
    cout<

And now the definition of SubscriptHandler to make the previous code work. It only shows how it can be done. This solution is optimal nor bug-free (not threadsafe for instance).

#include 
#include 
#include 
#include 
#include 

using namespace std;

template  class SubscriptHandler;

template class SubscriptHandler_ {

    ClassType*obj;
    array *arr;

    typedef SubscriptHandler_ Subtype;

    friend class SubscriptHandler_;
    friend class SubscriptHandler;

public:

    Subtype operator[](const ArgType& arg){
        Subtype s;
        s.obj = obj;
        s.arr = arr;
        arr->at(Recursion)=arg;
        return s;
    }
};

template class SubscriptHandler_ {

    ClassType*obj;
    array *arr;

    friend class SubscriptHandler_;
    friend class SubscriptHandler;

public:

    RetType operator[](const ArgType& arg){
        arr->at(0) = arg;
        return obj->callSubscript(*arr);
    }

};


template class SubscriptHandler{

    array arr;
    ClassType*ptr;
    typedef SubscriptHandler_ Subtype;

protected:

    SubscriptHandler() {
        ptr=(ClassType*)this;
    }

public:

    Subtype operator[](const ArgType& arg){
        Subtype s;
        s.arr=&arr;
        s.obj=ptr;
        s.arr->at(N-1)=arg;
        return s;
    }
};

template struct SubscriptHandler{
    RetType operator[](const ArgType&arg) {
        array arr;
        arr.at(0)=arg;
        return ((ClassType*)this)->callSubscript(arr);
    }
};