I need to overload [] operator in class Sparse Matrix. This operator must work like in 2D table access. For example tab[1][1], return reference.

The problem is I have a vector of elements(struct).

```
template <class T>
struct element
{
int x;
int y;
T Value;
};
```

If I want to access some field, I must store 2 coordinates from operator. I don't know how to do it.

```
class ElementProxy
{
Container* myOwner;
int myRowIndex;
int myColumnIndex;
public:
ElementProxy( Container* owner, int rowIndex, int columnIndex )
: myOwner( owner )
, myRowIndex( rowIndex )
, myColumnIndex( columnIndex )
{
}
operator Type() const // lvalue to rvalue conversion
{
return myOwner->get( myRowIndex, myColumnIndex );
}
void operator=( Type const& rhs ) const
{
myOwner->set( myRowIndex, myColumnIndex, rhs );
}
};
class RowProxy
{
public:
RowProxy( Container* owner, int rowIndex )
: myOwner( owner )
, myRowIndex( rowIndex )
{
}
ElementProxy operator[]( int columnIndex ) const
{
return ElementProxy( myOwner, myRowIndex, columnIndex );
}
};
```

To obtain a natural syntax, have your matrix class return a row object which also overloads the [] operator and in turn returns the element.

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