重写平等运算符

Question

I've implemented a class that overloads the == and != operators.

This seems to work fine; however, I get the warning 'type' defines operator == or operator != but does not override Object.Equals(object o) .

Okay, so I implemented Equals. But now I get the warning 'type' defines operator == or operator != but does not override Object.GetHashCode() .

Does this end at some point? Or have I wandered into a never-ending trail of requirements just because I want to overload == and != ?

Answer 1

Does this end at some point?

Yes, once you implement GetHashCode it will end. Eric Lippert has blogged about its importance . All I can do is suggest you to read and trust him :-)

Answer 2

Yes, it will end when you override GetHashCode .

When implementing equality operators, and furthermore Equals , it is the responsibility of the programmer to provide an implementation to deliver a custom hash code for that type.

See this MSDN reference for details.