Disallow null references in safe code?

[deadalnix]

On Tuesday, 4 February 2014 at 14:54:35 UTC, Adam D. Ruppe wrote:
> This gives us:
>
> * Implementation help - no binary cost for Nullable!Object 
> since it just uses null directly instead of a bool isNull field 
> (the optimizer also knows this)
>

static if(isReferenceType!T) {
     union {
         T t;
         typeof(null) __;
     }
}

> * Consistency with all other types. Nullable!int works, 
> Nullable!Object can be passed to a template, inspected, etc. 
> without new traits for isNullable and everything.
>

I'm not sure I understand that.

> * Library functionality so we can also make other types that do 
> the same kind of thing
>

I'm really confused now. What are you defending ??

> Then, if we did the Type? syntax, it would just be rewritten 
> into Nullable!Type. Nullable's definition would probably be in 
> the auto-imported object.d so it always works.

??????