Için basit anahtar C# IStructuralEquatable nedir örtüsünü

Için basit anahtar C# IStructuralEquatable nedir örtüsünü

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If two objects compare bey equal, the GetHashCode method for each object must return the same value. However, if two objects do not compare bey equal, the GetHashCode methods for the two object do derece have to return different values.

In this case you don't want to change your class implementation so you don't wantoverride the Equals method. this will define a general way to compare objects in your application.

g. MyType and Object) which will still use the identity comparison. I suspect it's not 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

IStructuralEquatable is an interface in C# that defines methods for determining whether two objects are structurally equal. It's often used in scenarios where you want to compare the structure of objects, typically within collections, and not just compare references or individual values.

This code technically works, but is sort of a hot mess and is derece really maintainable. Anyone using the library would have to write this code bey well. The next logical step would be to just use .Equals on the entire metrics.

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If those objects do hamiş contain equality/hashcode methods that satisfy that contract, you will have to wrap them and provide correct implementations for those methods yourself in the wrapper.

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

The reason why you need the IStructuralEquatable is for defining a new way of comparision that would be right for all the objects .

In all my years of development and blogging I never thought I would be writing about how amazing a C# struct is, how awesome IEquatable is, and how C# 7 features make implementing all of it mind blowing.

GitHub'da bizimle ortaklık örgün Bu gönülğin kaynağı GitHub'da bulunabilir; burada başkaca problemlerı ve çekme isteklerini oluşturup gözden geçirebilirsiniz. Daha lüks bili derunin yardımda mevcut kılavuzumuzu inceleyin.

Now that our struct is immutable the actual issue comes up when you need to compare these values. When I started to write the code to fix the bug I just decided that "hey I have the old values, I can just compare each of them":

Just look at the default ValueType.Equals(object) code that gets called otherwise. It's an absolute performance killer that introduces boxing, type evaluation and finally falls back on reflection if any of the fields are reference types.

However, this is hamiş 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 C# IStructuralEquatable Kullanımı version of Equals, which falls back to boxing :(