Are you sure it doesn't work?  On 2.063, this works:

```d
import std.stdio;

auto ref T[] foo(T)(auto ref T[] t)
{
    t ~= 1;
    return t;
}

void main()
{
    int[] x;
    foo(x[]);
    writeln(x);
    foo(x);
    writeln(x);
}
```

```
$ ./testautoref 
[]
[1]
```

Am I missing something?