Hi everyone, so dmd includes several -preview flags and I was wondering if there were any that are recommended to enable?

I like using the most up to date stuff possible so I've actually been using -preview=all and it seems to work alright, but then I hit a weird issue with sumtypes and -preview=dip1021 so I'm wondering if that's a bad idea.

Some of the previews seem pretty ok to use like the bugfix previews but I'm not sure about the DIPs. Like, is it required for me to use -preview=dip1000 to have scope do anything, for example? Cheers!

On Friday, 30 May 2025 at 00:31:56 UTC, luafyn wrote:

None, its all stuff that makes less code work, several of them have been there for years with known fundamental flaws.

On Friday, 30 May 2025 at 00:31:56 UTC, luafyn wrote:

I think no

DIP1000 is under discussion for dropping.

Moreover I would suggest to not consider D as a language with plans and proper design team which have "recommended" things.
The dev team is severely understaffed and nobody is doing high-level design work.

And if you will think about D as a language where any hacker has some idea and some time/energy to push it - it can be added to the language, even if it is not working well with other parts of the language, or even if the implementation is not fully thought and not all corner cases were properly designed.

So working with D from that perspective should help you to properly identify preview flags as "I want this hack-feature for my hacking". Having this in mind should better describe them and overall D idea as a lang for lone-wolf experienced hackers.

Hope this helped to better feel D's zen

On Friday, 30 May 2025 at 00:31:56 UTC, luafyn wrote:

I always use -preview=all, this also buys you dip1000, but otherwise the list is just too long and everything else has never annoyed me and was helpful several times.