On Sat, 24 Aug 2024 at 21:46, IchorDev via Digitalmars-d <digitalmars-d@puremagic.com> wrote:
On Saturday, 24 August 2024 at 09:11:34 UTC, user1234 wrote:
> On Saturday, 24 August 2024 at 08:06:21 UTC, IchorDev wrote:
>> I think everyone in this thread can agree that we need a
>> compiler-agnostic solution for changing the presumed hot-path,
>> and one that doesn’t require rewriting existing code more than
>> just adding on one word. For example, `if((x ==
>> y).expect(false)){}` makes it a pain to rewrite existing
>> `if`s, where `@unlikely if(x == y) {}` is easy.
>
> You also have the `pragma` option. I think that would be more
> adequate as not every vendor has to support it. In other words
> "dmd can just ignore it". Bonus: pragma can be attached to
> statements, that's not the case of attributes.

Like `pragma(likely, false)`? It’s a bit long, maybe
`pragma(unlikely)`? It’s something I’d want to use fairly often,
after all. Or we could just add some new grammar for adding
special modifiers to if statements. Something like…
```d
if: unlikely(x){
   //…
}
if(!x){
   //…
}else: likely{
   //…
}
```

C++ is way ahead on this... they added attributes to the language years back, and they defined [[likely]] and [[unlikely]] post-fix on control statements. It's really convenient, it reads well, and it's easy to retrofit without disturbing the code.
That's the de-facto now, and we should follow it.