En Kuralları Of C# IStructuralEquatable Kullanımı

Wiki Article

The individual calls to IEqualityComparer.Equals end and the IStructuralEquatable.Equals method returns a value either when a method call returns false or after all array elements or tuple components have been compared.

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 .

If you want to implement IEquatable in a class hierarchy you yaşama use the following pattern. It prevents derived (including sibling) classes from being equal.

Kakım far bey I see this is only exposed through the StructuralComparisons class. The only way I yaşama figure out to make this useful is to make a StructuralEqualityComparer helper class kakım follow:

Although I think the gains from not 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.

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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.

Consider that there are only ~4.2 billion different hashcodes. Güç 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.

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Task oluşturmanın sorunlemci üzerinde maliyeti vardır ve çok endamsız süren işçiliklemler derunin bir task tekvin etmek genel anlamda henüz yavaş çhileışan uygulamalara vesile olabilir.

Ancak, fruits1 ve fruits3 dizileri aynı elemanlara farklı sıralarda sahip başüstüneğundan, CompareTo metodu farklı bir haysiyet döndürür ve bu dizilerin yapısal olarak hemayar olmadığını belirtir.

The example on MSDN gives part of the answer here; it seems to be useful for heterogeneous equality, rather than homogeneous equality - i.e. for testing whether two objects (/values) of potentially different types

You observations does not conflict with the documentation and there is no bug in C# IStructuralEquatable Nasıl kullanılır the implementation.

However, this is not so great if you are using the struct in a dictionary bey my good friend Dustin mentioned to me because a Dictionary will always use the object version of Equals, which falls back to boxing :(