c++arraysoperatorsoperator-keyword

C++ [] array operator with multiple arguments?

Can I define in C++ an array operator that takes multiple arguments? I tried it like this:

const T& operator[](const int i, const int j, const int k) const{ 
    return m_cells[k*m_resSqr+j*m_res+i];
}

T& operator[](const int i, const int j, const int k){ 
    return m_cells[k*m_resSqr+j*m_res+i];       
}

But I'm getting this error:

error C2804 binary operator '[' has too many parameters
Solution

  • Prior to C++23, you could not overload operator[] to accept multiple arguments. As a workaround, you instead can overload operator(). (See How do I create a subscript operator for a Matrix class? from the C++ FAQ.)

    From C++23, as mentioned in a (deleted) answer by cigien, multiple subscript arguments can be passed to operator[] directly. See this demo from the cppreference page.