这是预期的C＃4.0元组的平等的行为？ [英] Is this expected C# 4.0 Tuple equality behavior?

问题描述

我看到不同的行为，使用.Equals之间==两间.NET 4.0的新的记录＆LT;>实例。如果我已重写等于元组和LT的对象;>，并呼吁.Equals的元组的Equals的覆盖将被调用。如果我使用==上的元组的Equals的覆盖不叫。那是由设计和是否有意义？

I'm seeing different behavior between using .Equals and == between two of .NET 4.0's new Tuple<> instances. If I have overridden Equals on the object in the Tuple<> and call .Equals on the Tuples the override of Equals will be called. If I use == on the Tuples the override of Equals is not called. Is that by design and does it make sense?

编辑：从答复和意见，我可以告诉我没有说清楚。我知道，元组LT;>为引用类型和引用类型==将检查身份（的ReferenceEquals）。但是，应该元组LT;>覆盖==检查它包含的对象平等？为了保持一致性，可能不是。

From answers and comments I can tell I'm not being clear. I know Tuple<> is a reference type and that for reference types == will check identity (ReferenceEquals). But, should Tuple<> override == to check equality of the objects it contains? For consistency, probably not.

例如，如果我有一个简单的对象

For example if I have a simple object

public class NameAndNumber
{
    public int Number { get; set; }
    public string Name { get; set; }

    public override bool Equals(object obj)
    {
        if (obj is NameAndNumber)
        {
            NameAndNumber other = (NameAndNumber)obj;
            return Number == other.Number && Name == other.Name;
        }

        return false;
    }
}

然后我做这样的事情：

and then I do something like this:

Tuple<NameAndNumber, NameAndNumber> left = new Tuple<NameAndNumber, NameAndNumber>(
      new NameAndNumber { Name = "one", Number = 1 }, 
      new NameAndNumber { Name = "two", Number = 2 });
Tuple<NameAndNumber, NameAndNumber> right = new Tuple<NameAndNumber, NameAndNumber>(
      new NameAndNumber { Name = "one", Number = 1 }, 
      new NameAndNumber { Name = "two", Number = 2 });
bool operatorResult = left == right;
bool equalsResult = left.Equals(right);
Console.Out.WriteLine("operatorResult = {0}  equalsResult = {1}", 
        operatorResult, equalsResult);

我得到operatorResult =假equalsResult =真

I get operatorResult = false equalsResult = true

我应该期待什么？

我知道就NameAndNumber的Equals的实现不是正确的，它只是简化了样品code。

I know the implementation of Equals on NameAndNumber isn't "right" it's just simplified sample code.

我也曾尝试实施IEquatable，==，！=，并GetHash code。同样的结果。

I have also tried implementing IEquatable, ==, !=, and GetHashCode. Same results.

推荐答案

您看到来自结果设计妥协，元组现在F＃和C＃之间共享。主要的一点是，所有元组确实实现为引用类型，这不是那么明显了。

The results you see come from a design compromise, Tuples are now shared between F# and C#. The main point is that all Tuples are indeed implemented as reference types, that was not so obvious.

元组是否应该做深或浅的平等检查的决定被转移到两个接口： IStructuralComparable ， IStructuralEquatable 。请注意，这些2现在也由Array类实现的。

The decision whether Tuples should do deep or shallow equality checks was moved to two interfaces: IStructuralComparable, IStructuralEquatable. Note that those 2 are now also implemented by the Array class.

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