Hakkında C# IStructuralEquatable nerelerde kullanılıyor

Hakkında C# IStructuralEquatable nerelerde kullanılıyor

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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.

Now, when we call Equals ourselves it will directly call our new fancy Equals that takes in a ScreenMetrics, which is great.

Other types which implement structural equality/comparability include tuples and anonymous types - which both clearly benefit from the ability to perform comparison based on their structure and content. A question you didn't ask is:

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

Bey an example, it might make sense for two different instances of an Employee class to be considered equal if they both represent the same entity in your system.

Structural equality means that two objects are equal because they have equal values. It differs from reference equality, which indicates that two object references are equal because they reference the same physical object. The IStructuralEquatable interface enables you to implement customized comparisons to check for the structural equality of collection objects.

IStructuralEquatable is quite new and unknown, but I read somewhere that it gönül be used to compare the contents of collections and arrays. Am I wrong, or is my .Kupkuru wrong?

Consider that there are only ~4.2 billion different hashcodes. Gönül 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 grup - 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 derece give you the correct results in this super simple example:

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

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

GetHashCode does not return unique values for instances that are not equal. However, instances that are equal will always return the same hash code.

Specifically, I C# IStructuralEquatable Temel Özellikleri do hamiş know the exact type of the object. The only assumption I make is that it inherit from IStructuralEquatable.