需要超负荷运营商的LT;与空检查 [英] needs overload operator< and null check

问题描述

I'm重载每种不超过运营商在C＃和我真的不知道这是否需要检查空。下面你可以找到一个例子：

I´m overloading the lessthan-operator in c# and I`m wondering whether this needs to check for null. Below you can find an Example:

public static bool operator <(MyClass x, MyClass y)
{
  if (x == null && y == null)
  {
    return false;
  }
  if (x == null)
  {
    return true; //false?
  }
  if (y == null)
  {
    return false; //true?
  }
  return x.Value < y.Value;
}

或者，这是正确的：

Or is this correct:

public static bool operator <(MyClass x, MyClass y)
{
  return x.Value < y.Value;
}

我didn't找到关于此的任何指令。但是，也许我错过了什么。

I didn´t find any instruction on this. But maybe I missed something.

推荐答案

问题的答案取决于你打算使用模式。如果您计划在空组合，愿与您考虑空值小于非空值，那么你的实现是正确的;如果您想考虑空值比非空对象时，则注释掉返回值（假和真正）应改为使用。如果你不打算允许空值的组合，抛出一个 ArgumentNullException 或允许的NullReferenceException 将是正确的选择。

The answer depends on your intended usage pattern. If you plan to have nulls in the mix, and you would like to consider null values to be less than non-null values, then your implementation is correct; if you would like to consider null values to be greater than non-null objects, then the commented out return values (false and true) should be used instead. If you do not plan to allow nulls in the mix, throwing an ArgumentNullException or allowing NullReferenceException would be the right choice.

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