Finding neighbours in a two-dimensional array

Question

Is there an easy way of finding the neighbours (that is, the eight elements around an element) of an element in a two-dimensional array? Short of just subtracting and adding

Answer 1

Grid (vector 2D or one dimension... not the problem here)
X & Y, coordinate of your element (or just pass your vector element by ref...)

int neighbour(const Grid & g, const size_t & x, const size_t & y) {
    for (int i = -1; i < 2; ++i)
        for (int j = -1; j < 2; ++j)
            if (x + i >= 0 && x + i < g.row && y + j >= 0 && y + j < g.col)
                //Do some stuff
    return 0;
}