overload operator[][] for 2d vector [duplicate]

Question

so currently i have to write a program in c++ where i have to create a class "CMyMatrix" and i wanted to know if its possible to overload the operator: "[][]"(i think technically they are 2 operators?) im using a 2d vector and would like the operator to work the same way as it works if you create a 2d array.

class CMyMatrix {
private:
    std::vector<std::vector<double>> matrix;
    int row_M = 0;
    int column_N = 0;
public:
    double& operator[][](int M, int N) { return something };
};

thank you for any help in advance.

Answer 1

This couldn't be done before C++23 since operator[] must have exactly one argument.

With the adoption of the multidimensional subscript operator in C++23, now you can

#include <vector>

class CMyMatrix {
private:
    std::vector<std::vector<double>> matrix;
    int row_M = 0;
    int column_N = 0;
public:
    double& operator[](int M, int N) { return matrix[M][N]; };
};

int main() {
  CMyMatrix m;
  m[0, 1] = 0.42;
}

Demo