gistfile1.txt

class ValueComparer<T> : IComparer<T>, IEqualityComparer<T>
{
    Func<T, T, int> comparer;
    Func<T, int> getHashCode;

    public ValueComparer(Func<T, T, int> comparer, Func<T, int> getHashCode = null)
    {
        this.comparer = comparer;
        this.getHashCode = getHashCode;
    }

    public int Compare(T x, T y)
    {
        return comparer(x, y);
    }

    public bool Equals(T x, T y)
    {
        return comparer(x, y) == 0;
    }

    public int GetHashCode(T value)
    {
        if (getHashCode == null)
            throw new NotSupportedException ();
        return getHashCode(value);
    }
}