En iyi Tarafı C# IStructuralEquatable Nasıl kullanılır

En iyi Tarafı C# IStructuralEquatable Nasıl kullanılır

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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?

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That is right! When we override Equals we must also override and implement GetHashCode. I am no HashCode expert, but in the same article from Sergey is a snippet of using a ValueTuple to simplify this entire call to 1 line of code just like our fancy ValueTuple Equality above.

LBushkinLBushkin 131k3333 gold badges217217 silver badges265265 bronze badges 11 8 Why birey't you just specify an IEqualityComparer yourself that does this? What does the IStructuralEquatable interface add to this?

It is used by the third example birli an argument to the Equals(Object, IEqualityComparer) method of the IStructuralEquatable interface that tuples implement. It compares two Double or two Single values by using the equality operator. It passes values of any other type to the default equality comparer.

– Royi Namir Commented Mar 3, 2012 at 18:04 @RoyiNamir user844541's answer is correct, but maybe it is still hard for you to understand without a concrete example, if you are familiar with IEqualityComparer and how it is used by Linq's Distinct(), then after check the source code to see how it implement IStructuralEquatable on referencesource.microsoft.com/#mscorlib/system/collections/…, then you will see how C# IStructuralEquatable nedir it work.

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 derece really sure if I really got it.

In my implementation I delegated the task of calculating hash codes to the internal array. While testing it, to my great surprise, I found that my two different arrays had the same structural hash code

comparer IEqualityComparer İki nesnenin yeksan olup olmadığını kıymetlendirmek için kullanılacak yöntemi teşhismlayan nesne.

In Xamarin.Essentials we use the C# struct all over the place to encapsulate "small groups of related variables" for our event handlers. They are groups of data that don't need to be created by the developers consuming the veri and are only really used for reading the veri.

Each of your objects should use a hashcode based on the contents of the object. If you have a value type containing 3 ints, use those when computing the hash code. Like this, all objects with identical content will have the same hash code, independent of app domain and other circumstances.

IStructuralEquatable is used with arrays to determine whether the arrays are structurally equal. The StructuralEqualityComparer.Equals method is used for this purpose.

Default property. The second time, it passes the default equality comparer that is returned by the StructuralComparisons.StructuralEqualityComparer property. The third time, it passes the custom NanComparer object. As the output from the example shows, the first three method calls return true, whereas the fourth call returns false.

However, this is hamiş so great if you are using the struct in a dictionary as my good friend Dustin mentioned to me because a Dictionary will always use the object version of Equals, which falls back to boxing :(