C# IStructuralEquatable Nasıl kullanılır Ile ilgili detaylı notlar

It's normally expected that if you implement IEquatable.Equals you will also override Object.Equals to be consistent. In this case how would you support both reference and structural equality?

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.

Reference types (read classes) don't benefit bey 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 derece 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:

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Your concern is that Object.GetHashCode() does not provide values that are stable and the concern is very valid birli emanet be seen in the first box headed by Caution in the documentation:

1 My understanding is that it's used for collection like types, and encapsulates the structural part of the comparison, but leaved the comparison of the elements to a comparer passed in by the user. But I'm hamiş really sure if I really got it.

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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)

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:

To C# IStructuralEquatable Kullanımı achieve this, employee objects with matching SSN properties would be treated birli logically equal, even if they were not structurally equal. Share Improve this answer Follow

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 birey 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.

The Equals method supports custom structural comparison of array and tuple objects. This method in turn calls the comparer object's IEqualityComparer.Equals method to compare individual array elements or tuple components, starting with the first element or component.

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