Pointers - Is it safe to point to invalid memory?

[Andy Valencia]

On Saturday, 16 August 2025 at 21:58:30 UTC, Paul Backus wrote:
> Creating a pointer that points out-of-bounds does not, by 
> itself, result in undefined behavior.
>
> However, such a pointer would not be considered a [safe 
> value][1], because dereferencing it *would* result in undefined 
> behavior.

I'm just pondering whether the intention was to accomodate this 
looping pattern:

```d
int sum_values(int* p, uint nval) {
   int result = 0;
   foreach(_; 0 .. nval) {
     result += *p++;
   }
   return result;
}
```

A C idiom (I've so very much embraced not using pointers in my D 
world) which technically leaves "p" pointing beyond the memory 
range.  Perhaps this is the special case being addressed?

Andy