Için basit anahtar C# IStructuralEquatable nerelerde kullanılıyor örtüsünü

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

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

Reference types (read classes) don't benefit as 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.

Daniel A.A. PelsmaekerDaniel A.A. Pelsmaeker 49.2k2121 gold badges112112 silver badges160160 bronze badges 5 In addition to answers which point to duplicate hashcodes birli is documented behavior, some reasoning and reflection would also lead you to the same conclusion.

It is used by the third example bey 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.

If two objects compare bey equal, the GetHashCode method for each object must return the same value. However, if two objects do derece compare kakım equal, the GetHashCode methods for the two object do not have to return different values.

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.

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

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I had the same question. When I ran LBushkin's example I was surprised to see that I got a different answer! Even though that answer katışıksız 8 upvotes, it is wrong. After a lot of 'reflector'ing, here is my take on things.

Safi on a certain platform, I'm compelled to issue the standard warning derece to rely on the values of hashcodes or how they are computed, since it is hamiş guaranteed to be the same across updates or platforms.

He, makalede nekais kabil. Bunu tenkit olarak akseptans ediyorum. Işlevsel programlamada struct kullanılmasının nedenini de bilmiyor, başarım ve öteki mevzular için da rastgele bir düşünüm çitndırmıdeğerlendirme. Siz biliyorsanız lütfen aydınlatır mkaloriız?

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. Kakım the output from the example shows, the first three method calls return true, C# IStructuralEquatable nerelerde kullanılıyor whereas the fourth call returns false.

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