using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SmartCoalApplication.Base
{
    [Serializable]
    public struct Pair<T, U>
    {
        private T first;
        private U second;

        public T First
        {
            get
            {
                return this.first;
            }
        }

        public U Second
        {
            get
            {
                return this.second;
            }
        }

        public override int GetHashCode()
        {
            int firstHash;
            int secondHash;

            if (object.ReferenceEquals(this.first, null))
            {
                firstHash = 0;
            }
            else
            {
                firstHash = this.first.GetHashCode();
            }

            if (object.ReferenceEquals(this.second, null))
            {
                secondHash = 0;
            }
            else
            {
                secondHash = this.second.GetHashCode();
            }

            return firstHash ^ secondHash;
        }

        public override bool Equals(object obj)
        {
            return ((obj != null) && (obj is Pair<T, U>) && (this == (Pair<T, U>)obj));
        }

        public static bool operator ==(Pair<T, U> lhs, Pair<T, U> rhs)
        {
            bool firstEqual;
            bool secondEqual;

            if (object.ReferenceEquals(lhs.First, null) && object.ReferenceEquals(rhs.First, null))
            {
                firstEqual = true;
            }
            else if (object.ReferenceEquals(lhs.First, null) || object.ReferenceEquals(rhs.First, null))
            {
                firstEqual = false;
            }
            else
            {
                firstEqual = lhs.First.Equals(rhs.First);
            }

            if (object.ReferenceEquals(lhs.Second, null) && object.ReferenceEquals(rhs.Second, null))
            {
                secondEqual = true;
            }
            else if (object.ReferenceEquals(lhs.Second, null) || object.ReferenceEquals(rhs.Second, null))
            {
                secondEqual = false;
            }
            else
            {
                secondEqual = lhs.Second.Equals(rhs.Second);
            }

            return firstEqual && secondEqual;
        }

        public static bool operator !=(Pair<T, U> lhs, Pair<T, U> rhs)
        {
            return !(lhs == rhs);
        }

        public Pair(T first, U second)
        {
            this.first = first;
            this.second = second;
        }
    }
}