NonNull template

[kdevel]

On Saturday, 19 April 2025 at 11:44:42 UTC, Jonathan M Davis 
wrote:
> [...]
>> > And with
>> >
>> > int* p = null;
>> > ref r = *p;
>> >
>> > no dereferencing occurs,
>>
>> In C++ this is a programming error. When creating a reference 
>> from a pointer the null check it is necessary in order to 
>> uphold
>> C++' guarantee that references are actually bound to existing 
>> objects.
>> [...]
>
> Well, if C++ now checks that pointer is non-null when creating 
> a reference from it, that's new behavior, because it most 
> definitely did not do that before.

Of course it doesn't and I didn't write that. I wrote that it is
a programming error to use a ptr to initialize a reference when
it is possible that the ptr is null. If refs in D were as strong
as in C++ I would write

     [... int *p is potentially null ...]
     enforce (p);
     auto ref r = *p;