On Friday, 25 September 2015 at 02:37:22 UTC, TheGag96 wrote:
What's the problem here? I SWEAR I've passed arrays by
reference before just like this. Thanks guys.
I'm seeing the same error, but I haven't yet determined why. At
any rate, this works:
```
import std.stdio;
void append(ref int[] arr, int val) {
arr ~= val;
}
void main() {
auto a1 = [10,20,30];
a1.append(40);
writeln(a1);
}
```
The compiler error aside, there's a big difference between this
function and your quicksort. This one is modifying the structure
(or metadata) of the source array. Your quicksort is only dealing
with the elements. You don't need to use ref to effect changes on
the elements of the source array. arr[1] = 2 on a function
parameter will be reflected in the source array even when ref is
absent. Only when you need to modify the length of the source
array, or cause it to point to a new memory block, would you need
to use ref.
So in your particular case, you can drop the ref from your
parameter and the compiler error will go away. However, the
function as written is producing a range violation :)
I'd still like to know what's causing the compiler error with ref
in this case, though.
