Question

I am trying to work with a multi-dimensional array in MSVS2010 console application, and I need to access members of a 2D array. I instantiate the array as

Thing::Thing(int _n){
    // size of the array
    this.m = _n;
    thing = new int*[m];
    for(int ii = 0; ii < m; ii++){
        thing[ii] = new int[m];
    }
}

this is working fine. though when I go to do a operator=, or operator== that both use the similar structure of:

Thing& Thing::operator=(const Thing & _thing){
    for(int ii = 0; ii < m; ii++){
        for(int jj = 0; jj < m; jj++){
            thing[ii][jj] = _thing[ii][jj]; //error thrown on this line
        }
    }
    return *this;
}

this throws 2 errors

binary "[": 'const Thing' does not define this operator or a conversion to a type acceptable to the predefined operator
IntelliSense: no operator"[]" matches these operands

this doesn’t make sense as it is an array of type int, and the “[]” operators have not been altered not to mention that error highlighting only puts it under:

_thing[ii][jj];

I can kinda live without the assignment operator, but I need the comparison operator to have functionality.

Answer 1

I think you’ve got your “thing”-s confused. Since:

   Thing& Thing::operator=(const Thing & _thing)

you probably want to have:

   thing[ii][jj] = _thing.thing[ii][jj];

_thing is the Thing object

_thing.thing is the multidimensional array