Keep in mind that for this interface to work correctly, the types within the collection or structure must also implement IStructuralEquatable or provide their own structural equality logic.
Now, when we call Equals ourselves it will directly call our new fancy Equals that takes in a ScreenMetrics, which is great.
The following example creates two identical 3-tuple objects whose components consist of three Double values. The value of the second component is Double.NaN. The example then calls the Tuple.Equals method, and it calls the IStructuralEquatable.Equals method three times. The first time, it passes the default equality comparer that is returned by the EqualityComparer.
Do hamiş fear because if you simply implement IEquatable the dictionary will use the strongly typed version! The nice thing is that we kind of actually already did this! So now we just have to do this:
Although I think the gains from not boxing will be less than the cost for having CanEqual. In that case you should seal your types and you no longer need CanEqual. Sealing also has some performance benefits.
– 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 it work.
What does IEquatable buy you, exactly? The only reason I sevimli see it being useful is when creating a generic type and C# IStructuralEquatable nedir forcing users to implement and write a good equals method.
Coming soon: Throughout 2024 we will be phasing out GitHub Issues bey the feedback mechanism for content and replacing it with a new feedback system. For more information see: .
Coming soon: Throughout 2024 we will be phasing out GitHub Issues birli the feedback mechanism for content and replacing it with a new feedback system. For more information see: .
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 özgü 8 upvotes, it is wrong. After a lot of 'reflector'ing, here is my take on things.
Net on a certain ortam, I'm compelled to issue the standard warning not to rely on the values of hashcodes or how they are computed, since it is not guaranteed to be the same across updates or platforms.
The contract of Equals differs from that of IStructuralEquatable, in that it indicates whether 2 objects are logically equal.
There is no need for an equality operator that accepts different types. That should hamiş even compile. So this is a very weak excuse for having a non-generic interface that works with objects.
Being able to specify IStructuralEquatable/IStructuralComparable in such cases is actually useful. It would also be inconvenient to pass a TupleComparer or ArrayComparer everywhere you want to apply this type of comparison. The two approaches are derece mutually exclusive.