为什么 Rider 建议我使用解构？

Question

我正在写这个class:

private class SameCellsComparer : EqualityComparer<Links> 
{
    public override bool Equals(Links t1, Links t2)
    {
        return t1 == null || t1.Equals(t2);
    }
    public override int GetHashCode(Links t)
    {
        // we suppose there will always be less than 100 000 000 items:
        return t.Item1.id + t.Item2.id * 100000000;
    }
}

但是 Rider 建议我在 GetHashCode(Links t) 上使用解构，如果我应用他的建议，我会得到这个：

private class SameCellsComparer : EqualityComparer<Links> 
{
    public override bool Equals(Links t1, Links t2)
    {
        return t1 == null || t1.Equals(t2);
    }
    public override int GetHashCode(Links t)
    {
        // we suppose there will always be less than 100 000 000 items:
        (Cell item1, Cell item2) = t;
        return item1.id + item2.id * 100000000;
    }
}

请不要说做坏事GetHashCode()原则，我只是求转换成(Cell item1, Cell item2) = t：是不是更安全、更快、更干净？没看懂。

Answer 1

那只是一个语法糖。通过解构，您可以控制元组项的名称。

检查这个 gist 我创建的。

为此 C# 代码：

using System;
public class C {
    public void M() {
        (string fff,String fff2) = C.Do();
        
        var l = C.Do();
    }
    
   public static (String a, String b) Do(){
       return ("aaa", "bvvvv");
   }
}

编译器是这样看的：

using System;
using System.Diagnostics;
using System.Reflection;
using System.Runtime.CompilerServices;
using System.Security;
using System.Security.Permissions;

[assembly: CompilationRelaxations(8)]
[assembly: RuntimeCompatibility(WrapNonExceptionThrows = true)]
[assembly: Debuggable(DebuggableAttribute.DebuggingModes.Default | DebuggableAttribute.DebuggingModes.DisableOptimizations | DebuggableAttribute.DebuggingModes.IgnoreSymbolStoreSequencePoints | DebuggableAttribute.DebuggingModes.EnableEditAndContinue)]
[assembly: SecurityPermission(SecurityAction.RequestMinimum, SkipVerification = true)]
[assembly: AssemblyVersion("0.0.0.0")]
[module: UnverifiableCode]
public class C
{
    public void M()
    {
        ValueTuple<string, string> valueTuple = Do();
        string item = valueTuple.Item1;
        string item2 = valueTuple.Item2;
        ValueTuple<string, string> valueTuple2 = Do();
    }

    [return: TupleElementNames(new string[] {
        "a",
        "b"
    })]
    public static ValueTuple<string, string> Do()
    {
        return new ValueTuple<string, string>("aaa", "bvvvv");
    }
}

注意这一行：

  ValueTuple<string, string> valueTuple = Do();
        string item = valueTuple.Item1;
        string item2 = valueTuple.Item2;
        ValueTuple<string, string> valueTuple2 = Do();

代码大致相同。

为什么 Rider 建议我使用解构？

Why does Rider suggests me to use deconstruction?

c#

rider