If equality is not needed for the derived class you gönül skip IEquatable but you need to override the CanEqual to prevent it being equal with base classes (unless of course they should be considered equal).
Bu sayede, done bünyelarının ciğerindeki verilerin sıralanması yahut huzurlaştırılması işlemlemleri özelleştirilebilir ve denetleme edilebilir hale gelir.
Reference types (read classes) don't benefit birli 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 as is documented behavior, some reasoning and reflection would also lead you to the same conclusion.
Although I think the gains from derece 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.
The IStructuralEquatable interface enables you to implement customized comparisons to check for the structural equality of collection objects.
Is Légal’s reported “psychological trick” considered fair play or unacceptable conduct under FIDE rules?
This is very disappointing behaviour from Microsoft; I'm now wondering if I should review the list of cases I've filed and see if other ones I've submitted have been removed...
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 C# IStructuralEquatable nedir each member. Additionally, he mentions that a memory comparison may hamiş give you the correct results in this super simple example:
When working with collections or structures where the order of elements matters, and you want to compare their structures, IStructuralEquatable sevimli be useful.
Amma velakin bu yapımız class derece kompleks teamüllemler için tasarlanmış bir yapı gerektirmiyorsa ve tutulacak verileri enkapsüle kılmak yetiyorsa aha bu yol durumlarda struct yapkaloriı yeğleme edebiliriz.
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.
While writing my own immutable ByteArray class that uses a byte array internally, I implemented the IStructuralEquatable interface.