Re: overloading the [] operator

"Axter" <>
3 Jun 2006 22:39:41 -0700
Joseph Paterson wrote:


I've created a class to store 2 dimensional matrices, and I've been
trying to overload the [] operator, so access to the elements of the
matrix is easy. I have 3 private variables, _m, _row and _col which are
respectively the array to store the data in, the number of rows and the
number of columns. _m is of type T, and is size _row * _col * sizeof

I've managed to overload the subscript operator like this:
T & operator [] (int n)
     return (_m[n * _col]);

but I don't understand why you can't do:
T * operator [] (int n)
     return (&_m[n * _col]);

instead. The first one works fine, but with the second one when I try
something like m[0][0] = 100.0, m[0][0] comes up as being an invalid
Could someone help me out here?

It should be something like the following:
T* operator[](int n) {return m_ + (col_*n);}

Check out the following link for an example:

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