Is it possible to implement mixins in C#?

c# extension-methods mixins
Stewart Johnson picture Stewart Johnson · Nov 1, 2008 · Viewed 31.1k times · Source

I've heard that it's possible with extension methods, but I can't quite figure it out myself. I'd like to see a specific example if possible.

Thanks!

Answer

Jon Skeet picture Jon Skeet · Nov 1, 2008

It really depends on what you mean by "mixin" - everyone seems to have a slightly different idea. The kind of mixin I'd like to see (but which isn't available in C#) is making implementation-through-composition simple:

public class Mixin : ISomeInterface
{
    private SomeImplementation impl implements ISomeInterface;

    public void OneMethod()
    {
        // Specialise just this method
    }
}

The compiler would implement ISomeInterface just by proxying every member to "impl" unless there was another implementation in the class directly.

None of this is possible at the moment though :)

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