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digitalmars.D - Upcoming bitfield and adam's call to make it even better

reply ryuukk_ <ryuukk.dev gmail.com> writes:
If you didn't know, bitfields just landed in the latest beta!

https://dlang.org/changelog/2.101.0.html#dmd.bitfields

Definitely a huge improvement over the current way of doing 
bitfields (import module + template) (in my opinion)

However, in his blog, adam has some interesting concerns about 
it, and shared a proposal on how it could be made better

I personally like his proposal, i would love to hear what Walter 
thinks about it!

It takes what C offers, and make it safer to use! it's exactly a 
BetterC language!

(btw, we could do the same for tagged union and .enum ;) ;) ;) ;) 
;) ;) ;), just dropping this idea here)


Here is the link of adam's blog post: 
http://dpldocs.info/this-week-in-d/Blog.Posted_2022_09_12.html#d-bitfields-could-be-good
Oct 18 2022
next sibling parent reply Dave P. <dave287091 gmail.com> writes:
On Tuesday, 18 October 2022 at 19:11:35 UTC, ryuukk_ wrote:

 If you didn't know, bitfields just landed in the latest beta!

 [...]


As I said in the other thread, I think we need both. Both 
extern(C) bitfields to match what C is doing and D bitfields that 
can actually be good and portable across different systems/ABIs.
Oct 18 2022
parent test123 <test123 gmail.com> writes:
On Tuesday, 18 October 2022 at 21:07:51 UTC, Dave P. wrote:

 On Tuesday, 18 October 2022 at 19:11:35 UTC, ryuukk_ wrote:

 If you didn't know, bitfields just landed in the latest beta!

 [...]


 As I said in the other thread, I think we need both. Both 
 extern(C) bitfields to match what C is doing and D bitfields 
 that can actually be good and portable across different 
 systems/ABIs.


extern(C) bitfields could be very userful when you need translate 
c to d
Oct 20 2022
prev sibling parent Quirin Schroll <qs.il.paperinik gmail.com> writes:
On Tuesday, 18 October 2022 at 19:11:35 UTC, ryuukk_ wrote:

 Here is the link of Adam's blog post: 
 http://dpldocs.info/this-week-in-d/Blog.Posted_2022_09_12.html#d-bitfields-could-be-good


The syntax Adam proposes is this:
```d
ulong fields {
       msb : 1,
       _reserved: 62,
       lsb: 1,
};
```

Personally, I don’t like the idea of taking the syntax `Type 
Identifier { }` for something as niche as bit fields. If we ever 

close it unnecessarily. The fix is rather easy: Remove the name:

```d
ulong
{
     msb: 1; // semi colon
     _reserved: auto; // auto (allowed at most once) = ulong’s 
bits minus given bits.
     lsb: 1;
} // no semi colon
```

It still should have a auto-generated name for the allMembers 
trait. If *you* want a name, use an anonymous union:

```d
union
{
     ulong bitfields;
     ulong
     {
         msb: 1;
         _reserved: auto;
         lsb: 1;
     }
}
```
Oct 20 2022