En son beş C# IStructuralEquatable Kullanımı Kentsel haber

En son beş C# IStructuralEquatable Kullanımı Kentsel haber

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If equality is not needed for the derived class you hayat 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).

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:

Equals and object.ReferenceEquals. Equals is meant to be overridden for whatever sort of comparison makes the most sense for a given type, whereas ReferenceEquals güç't be overridden and always compares by reference.

Let us hamiş forget about additional operators and not just relying on Equals. We birey implement the == and != operators easily:

comparer IEqualityComparer An object that determines whether the current instance and other are equal.

The IStructuralEquatable interface enables you to implement customized comparisons to check for the structural equality of collection objects. This is also made clear by the fact that this interface resides in the System.Collections namespace.

When an implementer overrides the virtual Equals method in a struct, the purpose is to provide a more efficient means of performing the value equality check and optionally to base the comparison on some subset of the struct's field or properties.

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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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 C# IStructuralEquatable nerelerde kullanılıyor 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.