, SteveRichter wrote

*snip*

a mixin is created by creating a new class that is based on the class being extended?

http://www.jakesee.com/2009/04/c-mixins-a-powerful-concept/

I have a class library that is returning an instance of a class. How to apply the mixin pattern to an object that already exists?

 

Indeed, mixins, at least the mixins I've seen are no substitute for extension methods at all.

I like the |> pipe operator in F# but in terms of tool and user friendliness, nothing beats extension methods. Dot dot dot...