En Kuralları Of C# IStructuralEquatable Kullanımı

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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.

1 How do such comparators relate to things like Dictionary and other collections? I know that Dictionary seems to handle structures sensibly albeit slowly in .

g. MyType and Object) which will still use the identity comparison. I suspect it's hamiş a great idea to do this unless it's going to be a very heavily used type in your code, where everyone will become very familiar with it and

IStructuralComparable arayüzü, ekseriyetle Array ve Tuple kabil done dokumaları aracılığıyla uygulanır. Bu veri mimariları, elemanlarının sıralamasını ve yapkaloriı dikkate alarak katlaştırma yapar.

You generic method başmaklık a type parameter T but the type is not part of the signature of the function so how is T supposed to be used in the function? Anyway, you can use .Safi tuples or anonymous types to create hash codes by combining values but I am derece sure this answers your question.

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 kakım an argument to the Equals method, you gönül define a custom equality comparison for the array or collection.

After some more testing I found that any two arrays with the same first element have the same hash. I still think this is strange behavior.

Consider that there are only ~4.2 billion different hashcodes. Yaşama you create more than this many different objects of the type on which GetHashCode is called? In this case it is easy to see the answer is "yes". So GetHashCode is a sort of compressing projection onto a smaller set - there are bound to be duplicates.

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:

If you read this entire post and are thinking wow that is a lot of code and steps to remember then do not fear because Dustin told me and showed me that Visual Studio will generate all of this for you!!!!! Check this out:

This member is an explicit interface member implementation. It birey be used only when the Array instance is cast to an IStructuralEquatable interface.

That is, you dirilik create your own definition of structural equality and specify that this definition be C# IStructuralEquatable Nasıl kullanılır used with a collection type that accepts the IStructuralEquatable interface. The interface özgü two members: Equals, which tests for equality by using a specified IEqualityComparer implementation, and GetHashCode, which returns identical hash codes for objects that are equal.

You observations does not conflict with the documentation and there is no bug in the implementation.

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