Checking function parameters in Phobos

[Jonathan M Davis]

On Wednesday, November 20, 2013 19:53:43 Meta wrote:
> Yes. It is very important not to allow direct access to the
> underlying value. This is important for ensuring that it is not
> put in an invalid state. This is a mistake that was made with
> std.typecons.Nullable, making it useless for anything other than
> giving a non-nullable type a null state (which, in fairness, is
> probably all that it was originally intended for).

It's arguably pretty pointless to put a nullable type in 
std.typecons.Nullable. If you want a nullable type to be null, just set it to 
null.

- Jonathan M Davis