How does equality work in CsWinRT?

[benstevens48]

I'm upgrading a large C# UWP project from .Net Native to .Net 10 + CsWinRT. One thing I noticed is I got lots of warnings about reference vs value equality when using == between a projected class and either an interface or the object type. I can see that this is because the C# wrapping classes generated override the == operator. This suggests that the same wrapping instance is not always returned for the same COM object. But this seems problematic to me. What if I compare two projected interfaces using ==? Is it possible this will return false even though the interfaces belong to the same COM object? This would be a problem if so. Also, will any of this change with CsWinRT 3.0?

[dongle-the-gadget]

The operator compares the underlying pointer to the COM object, so it should be equal for the same COM object. Don't see that changing with CsWinRT 3.0

[benstevens48]

Yeah but my question is what if I have two interface instances and then compare them? They won't use any overloaded operator as far as I'm aware. I can't see how equality can work properly unless the same wrapper instance is always reused for the same com object (if any wrapper exists for that com object).

[dongle-the-gadget]

Depending on whether you obtained both instances from CsWinRT. If yes then CsWinRT's equality implementation will still work. If not then no. Overloaded operators are handled by the class (for unknown WinRT classes it's WinRT.IInspectable).

[benstevens48]

OK, had a good discussion in #2246 which confirmed that the == and Equals overloads are not needed and will probably be removed in CsWinRT 3.0.