//Names changed slightly to protect the wicked
  public interface IProvideBoolean {
    Boolean True { get; }
    Boolean False { get; }
  }

  public class BooleanProvider : IProvideBoolean {
    public Boolean True => true;
    public Boolean False => false;
  }

So.... SOLID.... If there's ever a third value for Boolean, I Will Be Ready.

See also: https://thedailywtf.com/articles/What_Is_Truth_0x3f_

Finally ready for trinary computing!

Then you go back and refactor the code to pull out the interface! I so hate interface abuse.

If you use names like Logger instead of ILogger, you don't even have to change all the names when you refactor to an interface! If you end up wanting a FileBasedLogger, you just rename the current implementation to StdoutLogger, create a Logger interface, create a FileBasedLogger, and change instantiation sites to build the instance you want.

> If you use names like Logger instead of ILogger, you don't even have to change all the names when you refactor to an interface!

But you want to, that's the point. You're making a drastic change to your code base, surely you want to inspect every place where that type is used.

Using IClass naming is considered best practice in the .Net world AFAIK. (I think Visual Studio and/or Resharper hints very clearly about this.)

> Using IClass naming is considered best practice in the .Net world AFAIK.

No, it's the opposite. IClass is the norm, for legacy reasons going all the way back to the early COM days (it all started with IUnknown[1]).

[1] https://msdn.microsoft.com/en-us/library/windows/desktop/ms6...

I know, I'm demonstrating one reason I think that's a bad best practice :) I recognize there's nothing most people can do about that, though!