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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?

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