Type Constraint

typeconstraint.cs

    public sealed class MyTuple<T1, T2> : IEquatable<MyTuple<T1, T2>>
    {
        // Create Instance for Comparing Against Self.
        // If we used type against Interface we can compare two values
        private static readonly IEqualityComparer<T1> FirstComparer = EqualityComparer<T1>.Default;
        private static readonly IEqualityComparer<T2> SecondComparer = EqualityComparer<T2>.Default;
        
        private readonly T1 _first;
        private readonly T2 _second;

        public MyTuple(T1 first, T2 second)
        {
            this._first = first;
            this._second = second;
        }

        public T1 First { get { return _first; } }
        public T2 Second { get { return _second; } }

        public bool Equals(MyTuple<T1, T2> myTuple)
        {
            if (myTuple != null &&
                 FirstComparer.Equals(_first, myTuple.First) &&
             SecondComparer.Equals(_second, myTuple.Second))
                return true;

            return false;
        }

        // We need to override the base class implementations as per Microsoft Docs 
        // https://docs.microsoft.com/en-us/dotnet/api/system.iequatable-1.equals?view=netframework-4.8#System_IEquatable_1_Equals__0_

        // Equals is always coupled with GetHashCode()
        public override bool Equals(Object someTuple)
        {
            MyTuple<T1, T2> theirTuple = someTuple as MyTuple<T1, T2>;
            return this.Equals(theirTuple);
        }

        public override int GetHashCode()
        {
            return FirstComparer.GetHashCode(_first) + SecondComparer.GetHashCode(_second);
        }

    }