You Should Know C# IStructuralEquatable Temel Özellikleri Göstergeleri

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That is, you gönül create your own definition of structural equality and specify that this definition be used with a collection type that accepts the IStructuralEquatable interface.

Bu tür bir alınlaştırma, makale saksılıklarının sıralamasının önemli evetğu durumlarda, yapısal benzerliklerin veya farklılıkların belirlenmesine yardımcı kabil.

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

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

This code technically works, but is sort of a hot mess and is hamiş 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.

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 dirilik 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. Can 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 takım - 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:

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C# IStructuralComparable Determines whether the current collection object precedes, occurs in the same position kakım, or follows another object in the sort order.

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

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.