Question

I have a class called SparseMatrix which contain a private vector of type Cell.
Cell is a structure that should hold x,y coords and a double value.
In addition, I would like that a different class called RegMatix will be able to declare a vector of type Cell also.

this is the struct:

struct Cell {
    Cell(int row,int col, Number value) {
        _cellRow = row;
        _cellCol = col;
        _val = value;
    }
    int _cellRow, _cellCol;
    Number _val;
};

this is sparseMatrix:

class SparseMatrix {

//second, i tried to place the Cell here, but in RegMatrix.cpp Cell was not recognized.

public:
    void Iterator(std::vector<Cell>::const_iterator &startElement,  
                  std::vector<Cell>::const_iterator &endElement) const;
private:
    std::vector<Cell> _matrix;
        //first i tried to place the struct here, but the above line did not recognize
        // Cell. then i placed it above the vector and it worked but RegMatrix.cpp did not recognize it.
};

in RegMatrix.cpp i would like to be able to declare:

std::vector<Cell>::const_iterator start,end;

Eventually i placed it out side the class and it works fine, but is this the correct place for this definition?
And one last question, if I want that other classes would be able to read-only the struct data, is struct the correct structure for Cell or should i create a different class called Cell?

Sorry for the long question, Thank you all!

Answer 1

If you declare Cell inside of SparseMatrix, you have to scope it to be inside SparceMatrix.

For example:

std::vector<SparceMatrix::Cell>::const_iterator start,end;

You currently have it globally scoped.

As to the best place, if you only use Cell in SparceMatrix, I would declare it in there.