Overloading operator== versus Equals()

Question

I\'m working on a C# project on which, until now, I\'ve used immutable objects and factories to ensure that objects of type Foo can always be compared for equal

Answer 1

It definitely smells. When overloading == you should make sure that both Equals() and GetHashCode() are also consistent. See the MSDN guidelines.

And the only reason that this seems OK at all is that you describe your type as immutable.