Smart pointers instead of GC?

[Walter Bright]

On 2/2/2014 9:30 AM, Namespace wrote:
> Sounds good. But why @nullable instead of C# choice of "Type?" ?

Let me rephrase that as "why use a storage class rather than a type constructor?"

An excellent question.

One of the big problems with a type constructor is we've already got a number of 
them - const, immutable, shared, inout. These and their conversions have taken 
quite a while for people to get comfortable with, and there are still some 
issues in the language arising from their interactions.

Adding another type constructor will double the number of cases. I worry that D 
would collapse under the strain. This applies as well to type constructors for 
"borrowed", etc.

On the other hand, D took the risky leap into the unknown by making 'ref' a 
storage class rather than a type constructor (in C++ it's a type constructor). 
This has turned out to be a satisfying win. I suspect it will be for @nullable, 
too, though we have to work through the cases to find out for sure.