Just curious. What things bother you about C#'s COM interop?

Where to start... well my first complaint would be that even when you have an existing type library, the automatic import (w/ .NET 2003 anyways) often leaves something to be desired. For example, my current project I'm working on imports ShDocVw.dll. So there's a nice happy Interop.ShDocVw.dll file sitting in my project directory. However, the types seem to be imperfectly loaded into the IDE. For example, AxSHDocVw.DWebBrowserEvents2_BeforeNavigate2Event shows no members in the Object Browser; however, that information does exist in the interop assembly, since ildasm shows all the members happily, and using those members in source code compiles properly.

But when you don't have a type library, that's where the real fun begins. COM interfaces are represented by C# interfaces, which is fair enough. However, C# interfaces can't inherit from one another, which means that instead if you need to write an interface class with inheritance, you need to manually duplicate the function signatures in the child interfaces, and in implementation classes, you have to remember in implement both the child and the parent interfaces. Otherwise you might have strangeness like IPersistStreams that aren't IPersists. This is a level of hassle that implementing a COM interface in C++ doesn't have. And I don't think I should have to explain just how wrong *that* is.

Then you have the joy of decoding function signatures from IDL files or C/C++ headers into C# declarations. And there's decomposing structure types as well. When all is said and done, with the attributes you need to plaster on everything to make sure that everything is compatible, you've probably written more code than the equivalent C++ implementation, and you're less sure that everything works properly (should I have declared this as a [MarshalAs(UnmanagedType.Interface)] out Object or maybe a [MarshalAs(UnmanagedType.IUnknown)] ref Object?). See the above just wrong comment.

I could go on, but there's not much point. Let's just say I'm looking forward to the next version of C# to see if they streamlined things any better.