Good discussion and I would love more lightweight type creation in C++.

The "Allow internal functionality" proposal doesn't fully work as-is. Imagine you have a type Scalar, which has a function:

  Scalar Scalar::scale(Scalar);

If you now do

  typedecl Scalar Celcius;

you'd get a function for it with the following signature:

  Celcius Celcius::scale(Celcius);

However, the function you'd actually want is

  Celcius Celcius::scale(Scalar);

The root problem here is that since the original type mixes different uses of the type, you can't blindly convert all those uses to the new type.