opIndexUnary post in-/decrement how to ?

[wjoe]

On Wednesday, 14 July 2021 at 12:49:58 UTC, Tejas wrote:
>
> I think it's a bug, because the following works:
>
> ```d
>
> import   std.stdio;
>
> struct abc{
>     int[100] a;
>     int opIndex(int index){
>         return a[index];
>     }
>     int opIndexUnary(string s)(int index)
>         if(s == "++"){
>         return ++a[index];
>         }
>     int[] opUnary(string s)() if (s == "++"){
>         return a[] += 1;
>     }
> }
>
> void main (){
>     abc s;
>     int[100] a;
>     int temp;
>     writeln (a[20]++);
>
>     writeln(a[20]);
>
>     writeln(++s[20]);
>
>     writeln(s[20]);
>
>     //writeln(s[0]++);// doesn't work for some reason
>
>     writeln(s[0]);
>
>     writeln(s++);//but this works!!
>
>     writeln(s);
> }
>
> ```

```D
writeln(++s[0]); // should work
writeln(s++); // this calls opUnary if I'm not mistaken
```