Is C# 4.0 Tuple covariant
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by RichK
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Published on 2010-05-20T10:28:20Z
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2010/05/20
10:30 UTC
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(I would check this out for myself, but I don't have VS2010 (yet))
Say I have 2 base interfaces:
IBaseModelInterface
IBaseViewInterface
And 2 interfaces realizing those:
ISubModelInterface : IBaseModelInterface
ISubViewInterface : IBaseViewInterface
If I define a Tuple<IBaseModelInterface, IBaseViewInterface>
I would like to set that based on the result of a factory that returns Tuple<ISubModelInterface, ISubViewInterface>
.
In C# 3 I can't do this even though the sub interfaces realize the base interfaces. And I'm pretty sure C# 4 lets me do this if I was using IEnumerable<IBaseModelInterface>
because it's now defined with the in
keyword to allow covariance. So does Tuple
allow me to do this?
From what (little) I understand, covariance is only allowed on interfaces, so does that mean there needs to be an ITuple<T1, T2>
interface? Does this exist?
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