I have a struct called Point. Point is pretty simple:

```
struct Point
{
    Row row;
    Column column;

    // some other code for addition and subtraction of points is there too
}

```

`Row` and `Column` are basically glorified `int`s, but I got sick of accidentally transposing the input arguments to functions and gave them each a wrapper class.

Right now I use a `set` of points, but repeated lookups are really slowing things down. I want to switch to an `unordered_set`.

So, I want to have an `unordered_set` of `Point`s. Typically this set might contain, for example, every point on a 80x24 terminal = 1920 points. I need a good hash function. I just came up with the following:

```
struct PointHash : public std::unary_function<Point, std::size_t>
{
    result_type operator()(const argument_type& val) const
    {
        return val.row.value() * 1000 + val.col.value();
    }
};

```

However, I'm not sure that this is really a good hash function. I wanted something fast, since I need to do many lookups very quickly. Is there a better hash function I can use, or is this OK?