C `restrict` keyword in D

[ag0aep6g via Digitalmars-d]

On 09/04/2017 06:10 AM, Moritz Maxeiner wrote:
> Indeed, but it also means that - other than null dereferencing - pointer 
> issues can by made into reference issues my dereferencing a pointer and 
> passing that into a function that takes that parameter by reference.

Why "other than null dereferencing"? You can dereference a null pointer 
and pass it in a ref parameter. That doesn't crash at the call site, but 
only when the callee accesses the parameter:

----
int f(ref int x, bool b) { return b ? x : 0; }
void main()
{
     int* p = null;

     /* Syntactically a null dereference, but doesn't crash: */
     f(*p, false);

     /* This crashes: */
     f(*p, true);
}
----