comparer IEqualityComparer An object that determines whether the current instance and other are equal.
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.
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:
Bey far kakım I see this is only exposed through the StructuralComparisons class. The only way I gönül figure out to make this useful is to make a StructuralEqualityComparer helper class kakım follow:
This code technically works, but is sort of a hot mess and is not really maintainable. Anyone using the library would have to write this code as 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 sevimli be used to compare the contents of collections and arrays. Am I wrong, or is my .Net wrong?
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 kaş - 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 hamiş give you the correct results in this super simple example:
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To achieve this, employee objects with matching SSN properties would be treated kakım logically equal, C# IStructuralEquatable nedir even if they were derece 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":
There is no need for an equality operator that accepts different types. That should derece even compile. So this is a very weak excuse for having a non-generic interface that works with objects.
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