On Monday, 23 April 2012 at 17:18:30 UTC, Namespace wrote:
> I thought that something like this
>
> // not_null_struct.d
>
> NotNull!(T) assumeNotNull(T : Object)(T t) {
> 	return NotNull!(T)(t);
> }
>
> @property
> NotNull!(T) makeNotNull(T : Object)() {
> 	T t = new T();
> 	
> 	return assumeNotNull(t);
> }
>
> // not_null.d which import not_null_struct.d
>
> NotNull!(Foo) _convert() {
> 	//return NotNull!(Foo)(this); // prints: Stack overflow
> 	return assumeNotNull(this);
> }
>
> alias _convert this;
>
> would allow me to convert Foo to NotNull!(Foo) implicit. But it doesn't work. I get this error:
>
> not_null.d(37): Error: template instance not_null_struct.assumeNotNull!(Foo) recursive expansion
>
> Line 37 is the return in the _convert method.
>
> Does anybody know why? I thought that would a smart idea...

I see, if i comment out "alias _get this;" in NotNull it works fine and i can implicit convert Foo to NotNull!(Foo).
But why doesn't it work shareable? In that case it would be nearly perfect for me.
Does anyone know how it could work? In my opinion both variants have to work shareable. Don't they?

After i'm sure, that this is a bug: Great work again.
If this bug will be fixed soon or someone can help me to find a workaround, then NotNull would be exactly what I always wanted.