C# IStructuralEquatable Kullanımı - Genel Bakış

C# IStructuralEquatable Kullanımı - Genel Bakış

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That is, you kişi create your own definition of structural equality and specify that this definition be used with a collection type that accepts the IStructuralEquatable interface.

Now, when we call Equals ourselves it will directly call our new fancy Equals that takes in a ScreenMetrics, which is great.

Reference types (read classes) don't benefit birli much. The IEquatable implementation does let you avoid a cast from System.Object but that's a very trivial gain. I still like IEquatable to be implemented for my classes since it logically makes the intent explicit.

Do not fear because if you simply implement IEquatable the dictionary will use the strongly typed version! The birçok thing is that we kind of actually already did this! So now we just have to do this:

Although I think the gains from hamiş boxing will be less than the cost for having CanEqual. In that case you should seal your types and you no longer need CanEqual. Sealing also saf some performance benefits.

The generic tuple classes (Tuple, Tuple, Tuple, and so on) and the Array class provide explicit implementations of the IStructuralEquatable interface. By casting (in C#) or converting (in Visual Basic) the current instance of an array or tuple to an IStructuralEquatable interface value and providing your IEqualityComparer implementation as an argument to the Equals method, you sevimli define a custom equality comparison for the array or collection.

The IStructuralEquatable interface enables you to implement customized comparisons to check for the structural equality of collection objects. This is also made clear by the fact that this interface resides in the System.Collections namespace.

The following example creates two identical 3-tuple objects whose components consist of three Double values. The value of the second component is Double.NaN. The example then calls the Tuple.Equals method, and it calls the IStructuralEquatable.Equals method three times. The first time, it passes the default equality comparer that is returned by the EqualityComparer.

Ray BooysenRay Booysen 29.6k1414 gold badges8686 silver badges111111 bronze badges 6 so when you are dealing with objects, is == assumed to only mean the exact same memory address (same instance)

I had the same question. When I ran LBushkin's example I was surprised to see that I got a different answer! Even though that answer katışıksız 8 upvotes, it is wrong. After a lot of 'reflector'ing, here is my take on things.

Net on a certain ortam, I'm compelled to issue the standard warning not to rely on the values of hashcodes or how they are computed, since it is derece guaranteed to be the same across updates or platforms.

Oldu, makalede eksiklikler mümkün. Bunu eleştiri olarak ikrar ediyorum. Fonksiyonel programlamada struct kullanılmasının nedenini bile bilmiyor, performans ve sair konular üzerine da herhangi bir fikir barındırmıversiyon. Siz biliyorsanız lütfen aydınlatır mısınız?

Default property. The second time, it passes the default equality comparer that is returned by the StructuralComparisons.StructuralEqualityComparer property. The third time, it passes the custom NanComparer object. Birli the output from the example shows, the first three method calls return true, whereas the fourth call returns false.

Bu alanda C# IStructuralEquatable Temel Özellikleri veya diğer bir alanda, benim ve özge yardımcı insanoğluın paylaşımlarına lütfen acizliğiniz ve ezikliğinizle yaklaşmayınız. İzin istemek, benim hükmüm şeşna girmeniz mealına gelmemektedir.