How can I get close to non-nullable reference type

问题:

I've read many of the non-nullable questions and answers. It looks like the best way to get close to non-nullable types in C# (4.0) is Jon Skeet's NonNullable<> hack.

However, it seems that C++/CLI has solved much of the problem by supporting managed references: Foo% (instead of native C++ Foo&). The compiler makes this work by adding modreq(IsImplicitlyDereferenced) to the argument. Trying to call such a function from C# results in:

'<FunctionName>' is not supported by the language

Is there anything better then NonNullable<>?

Is there any way to (reasonably--i.e., w/o using reflection) call a C++/CLI method Foo::Method(Bar%) from C#?

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[edit] It seems there is currently nothing better than NonNullable<>...I wish I would have gotten some comments on the C++/CLI stuff as it already has at least a partial solution.

回答1:

I've run into this a few times...I've yet to find anything better than Skeet's solution. It's solved all the cases I've come across, so I have to give it my vote.

I agree it's a bit of a hacky situation that we have to resort to that...but his fix does solve the problem.

回答2:

Yep, spec#: http://research.microsoft.com/en-us/projects/specsharp/

-- Edit: I just noticed you said C# 4.0; I'm fairly sure Spec# doesn't support that version. Nevertheless, it's worth a review.

You may also be able (I think) to check at a slightly later stage then compile, via a rule in Gendarme: http://www.mono-project.com/Gendarme (assuming that runs against 4.0)