Unexpectedly nice case of auto return type

[Basile B.]

On Wednesday, 4 December 2019 at 03:17:27 UTC, Adam D. Ruppe 
wrote:
> On Wednesday, 4 December 2019 at 01:28:00 UTC, H. S. Teoh wrote:
>> typeof(return) is one of the lesser known cool things about D 
>> that make it so cool.  Somebody should write an article about 
>> it to raise awareness of it. :-D
>
> you know i probably will write about that next week. so be sure 
> to like, comment, and subscribe so you never miss my next post 
> and then give me all your money on patreon so i can keep 
> bringing you content :P :P

I've just made the refact using typeof(null) and gained 78 SLOC
The pattern was:

     void issueError();

and then in the code, in a dozen a function returning different 
classes types

    if (...) {
         issueError();
         return null;
    }

now this becomes:

    typeof(null) issueError();

    if (...)
         return issueError();

I wish I knew that trick before. I prefer typeof(null) in case I 
would translate to another language. I tend to type the static 
type when I know it anyway.