En iyi Tarafı C# IStructuralEquatable Nasıl kullanılır

En iyi Tarafı C# IStructuralEquatable Nasıl kullanılır

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Keep in mind that for this interface to work correctly, the types within the collection or structure must also implement IStructuralEquatable or provide their own structural equality logic.

= to provide value equality checks (vs the default reference equality check). The MSDN documentation suggests you only do it for immutable types. There are also issues involving interfaces and operator overloading.

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 hamiş fear because if you simply implement IEquatable the dictionary will use the strongly typed version! The nice thing is that we kind of actually already did this! So now we just have to do this:

I'm amazed that the most important reason is not mentioned here. IEquatable was introduced mainly for structs for two reasons:

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 hayat define a custom equality comparison for the array or collection.

What does IEquatable buy you, exactly? The only reason I birey see it being useful is when creating a generic type and forcing users to implement and write a good equals method.

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.

Reading through the excellent blog post by Sergey on struct equality performance he mentions that the default implementations are pretty slow and using boxing for each member. Additionally, he mentions that a memory comparison may not give you the correct results in this super simple example:

When working with collections or structures where the order of elements matters, and you want to compare their structures, IStructuralEquatable can be useful.

Fakat, fruits1 ve fruits3 dizileri aynı elemanlara farklı sıralarda mevla evetğundan, CompareTo metodu farklı bir mesabe döndürür ve bu dizilerin strüktürel olarak hemayar olmadığını belirtir.

Bu strüktürya kadar oluşturduğumuz tüm nesnelerin Heap kısmında bulunduğunu söylemiştik. Oysa Stack kısmında struct konstrüksiyonsında nesneleri tutabilmekteyiz.

There is no need for an equality operator that accepts different types. That should hamiş even compile. So this is a very weak excuse for having a non-generic interface that works with objects.

Specifically, I C# IStructuralEquatable nerelerde kullanılıyor do not know the exact type of the object. The only assumption I make is that it inherit from IStructuralEquatable.