Will D ever get a reference type?

[Bill Baxter]

> Bill Baxter Wrote:
> 
>> Will D ever get a reference type?
>>
>> I don't think pointers are really sufficient.
>> The handy 'foo.bar' == '(*foo).bar' attribute access is nice, but it 
>> doesn't allow you to really manipulate values and pointers to values 
>> interchangeably.
>>
>> For instance, if I have an int pointer, x,  I can't do  (12 + x * 2) and 
>>   get integer math.  I get pointer math (if not an error).

Nick Sabalausky wrote:
 > You know you can just dereference the pointer like (12 + *x * 2), 
right? (Sorry if you already did). Or are you saying you don't like 
needing to dereference it like that?
 >

The latter.  D does go out of its way to try to remove the need for 
reference types ('.' can dereference a pointer, and opIndexAssign 
handles the a[i]=5), but there are still things you can't do.  Like 
implement op-increment indexing operators for a class/struct:
    a[i]+=5;
    a[i]-=5;
    a[i]*=5;
    a[i]/=5;
    a[i]++;
    a[i]--;
    ...
Or pass the result of a.opIndex(i) to a function that modifies the argument:
    setValue(a[i])  //calling void setValue(ref int i)

This means it's not possible to create an array-like class that's truly 
interchangeable with the built-in arrays.

It also affects properties.  If there were reference types then it would 
be possible (though some would argue not advisable) to have the 
op-increment work for property methods:
    a.x += 5;
where x is a member function like:
       ref int x() { return my_x; }


So really what I was wondering is if Walter considers D's current 
pointers plus reference parameters to be enough.

Are there any other things you can't currently do in D that reference 
types would allow?

--bb