using System;

using System.Collections;

using System.Collections.Generic;

using System.Collections.Immutable;

public class Program

{

    public static void Main()

    {

        var f1 = new Foo(new[] { 1, }.ToImmutableArray());

        var f2 = new Foo(new[] { 1, }.ToImmutableArray());

        var f3 = new Foo(new[] { 1, 2, }.ToImmutableArray());

​

        Console.WriteLine("f1 == f2: {0}", f1 == f2);

        Console.WriteLine("f1 == f3: {0}", f1 == f3);

        Console.WriteLine("f2 == f3: {0}", f2 == f3);

​

        Console.WriteLine();

​

        Console.WriteLine("f1 hashcode: {0}", f1.GetHashCode());

        Console.WriteLine("f2 hashcode: {0}", f2.GetHashCode());

        Console.WriteLine("f3 hashcode: {0}", f3.GetHashCode());

​

        Console.WriteLine();

        var b1 = new Bar(new[] { 1, });

        var b2 = new Bar(new[] { 1, });

        var b3 = new Bar(new[] { 1, 2, });

        Console.WriteLine("b1 == b2: {0}", b1 == b2);

        Console.WriteLine("b1 == b3: {0}", b1 == b3);

        Console.WriteLine("b2 == b3: {0}", b2 == b3);

        Console.WriteLine();

        Console.WriteLine("b1 hashcode: {0}", b1.GetHashCode());

        Console.WriteLine("b2 hashcode: {0}", b2.GetHashCode());

        Console.WriteLine("b3 hashcode: {0}", b3.GetHashCode());

    }

}

​

record Foo(ImmutableArray<int> Arr)

{

    public virtual bool Equals(Foo other)

    {

        if ((object)this != other)

        {

            if ((object)other != null && EqualityContract == other.EqualityContract)

            {

                var comparer = StructuralComparisons.StructuralEqualityComparer;

                return comparer.Equals(Arr, other.Arr);

            }

            return false;

        }

        return true;

    }

​

    public override int GetHashCode()

    {

        var comparer = StructuralComparisons.StructuralEqualityComparer;

        return (EqualityComparer<Type>.Default.GetHashCode(this.EqualityContract) * -1521134295)

            + comparer.GetHashCode(this.Arr);

    }

}

​

record Bar(int[] Arr)

{

    public virtual bool Equals(Bar other)

    {

        if ((object)this != other)

        {

            if ((object)other != null && EqualityContract == other.EqualityContract)

            {

                var comparer = StructuralComparisons.StructuralEqualityComparer;

                return comparer.Equals(Arr, other.Arr);

            }

            return false;

        }

        return true;

    }

​

    public override int GetHashCode()

    {

        var comparer = StructuralComparisons.StructuralEqualityComparer;

        return (EqualityComparer<Type>.Default.GetHashCode(this.EqualityContract) * -1521134295)

            + comparer.GetHashCode(this.Arr);

    }

}