C# requiring operator overloading

public class AutoAverage<T>
{
    public AutoAverage(Func<T, T, T> sum, Func<T, T, T> divide) { ...

public class AutoAverage<T>
{
    public AutoAverage(Func<T, T, T> sum, Func<T, T, T> divide) { ...

var autoAverage = new AutoAverage((x, y) => x + y, (x, y) => x / y);
// ... use it ...

interface ISumT<T>
{
  /// <summary>
  /// the sum method adds rhs to this and returns the result
  /// </summary>
  /// <remark>
  /// use a interface (i.e. ISumT)
  /// with a method (i.e. sum)
  /// because "where" doesn't support operators
  /// </remark>
  T sum(T rhs);
}

public class AutoAverage<T> where T : ISumT<T>
{
  public T NextAvg( T newValue )
  {
    // can assume that T implements the sum method
  }
}