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IComparable interface for partial ordering

I am trying to define a generic function to give the largest value for a set of parameters. It works like this:

    public static TResult Max<TResult>(params TResult[] items)
    {
        TResult result = items[0];
        foreach (var item in items)
        {
            if (item > result)
                result = item;
        }
        return result;
    }

This is all well and good, except that the compiler screeches on the "item> result" line. I need a way to restrict the TResult to have the> operator (or <will work too.) However, I don't see any interface available to do this. Since this is a partial ordering, this seems like a fairly common task. Am I missing something in the giant .NET documentation?

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2 answers


You can use IComparable

:



public static IComparable Max<TResult>(params IComparable[] items)
{
    IComparable result = items[0];
    foreach (var item in items)
    {
        if (item.CompareTo(result) > 0)
            result = item;
    }
    return result;
}
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There is no interface that only supports partial ordering. You also cannot use operators in generics.

The most common solution is to pass a comparator method delegate.



You can also use only part of the tags IComparable

or IComparer

that say "this is more than this" and ignore the other 2 values.

IComparable

and IComparer<in T>

that is used via LINQ queries. That is, see OrderBy .

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