NotNull pointers

[Dmitry Olshansky]

On 30.08.2011 0:22, Walter Bright wrote:
> For the latest dmd,
> https://github.com/D-Programming-Language/dmd/commit/1193f7828b444056c943742daae0a5ccf262272e
> ,
> I've implemented the ability to disable default initialization. This
> makes it practical to implement a library based "NotNull" type without a
> special syntax for it. The rationale for this is (rather than making it
> builtin) one can now build any type that is a restricted subset of
> another type. I suspect that a non-null type is just scratching the
> surface of this ability.
>

Nice!
Clean RAII with structs comes to mind, before you'd have to have .init 
to be as an invalid state that is always checked later on, e.g.:

File f;
f.write("blah");//will fail enforce inside write

I suspect it can get a bit tricky to deal with arrays of such types though.

-- 
Dmitry Olshansky