C#

class SOME_API SomeClass
{
public:
    // Accessors.
    bool operator==( const SomeClass& Other ) const
    {
        return Index == Other.Index;
    }

    bool operator!=( const SomeClass& Other ) const
    {
        return Index != Other.Index;
    }

    //...

private:
    // SomeClass index.
    int Index;

    //...
};

// An immutable int wrapper class
public class SomeClass : IEquatable<SomeClass>
{
    private int index;

    public SomeClass(int index)
    {
        this.index = index;
    }

    public static bool operator ==(SomeClass instance, SomeClass other)
    {
        if(object.ReferenceEquals(instance, other))
            return true;
        if(object.ReferenceEquals(null, instance) || object.ReferenceEquals(null, other))
            return false;
        return instance.index == other.index;
    }
    public static bool operator !=(SomeClass instance, SomeClass other)
    {
        return !(instance == other);
    }

    public int Index
    {
        get { return index; }
    }

    public override bool Equals(object obj)
    {
        return Equals(obj as SomeClass);
    }
    public bool Equals(SomeClass other)
    {
        if(object.ReferenceEquals(null, other))
            return false;
        return index.Equals(other.index);
    }
    public override int GetHashCode()
    {
        return index;
    }
}

// An immutable int wrapper struct
public struct SomeStruct : IEquatable<SomeStruct>
{
    private int index;

    public SomeStruct(int index)
    {
        this.index = index;
    }

    public static bool operator ==(SomeStruct instance, SomeStruct other)
    {
        return instance.index == other.index;
    }
    public static bool operator !=(SomeStruct instance, SomeStruct other)
    {
        return !(instance == other);
    }

    public int Index
    {
        get { return index; }
    }

    public override bool Equals(object obj)
    {
        if(obj is SomeStruct)
            return Equals((SomeStruct)obj);
        return false;
    }
    public bool Equals(SomeStruct other)
    {
        return index.Equals(other.index);
    }
    public override int GetHashCode()
    {
        return index;
    }
}