-preview switches

[Atila Neves]

On Wednesday, 1 April 2020 at 14:15:36 UTC, Steven Schveighoffer 
wrote:
> dmd '-preview=?'
>
> Upcoming language changes listed by -preview=name:
>   =all              list information on all upcoming language 
> changes
>   =dip25            implement 
> https://github.com/dlang/DIPs/blob/master/DIPs/archive/DIP25.md 
> (Sealed references)
>   =dip1000          implement 
> https://github.com/dlang/DIPs/blob/master/DIPs/other/DIP1000.md 
> (Scoped Pointers)
>   =dip1008          implement 
> https://github.com/dlang/DIPs/blob/master/DIPs/other/DIP1008.md 
> (@nogc Throwable)
>   =dip1021          implement 
> https://github.com/dlang/DIPs/blob/master/DIPs/accepted/DIP1021.md (Mutable function arguments)
>   =fieldwise        use fieldwise comparisons for struct 
> equality
>   =markdown         enable Markdown replacements in Ddoc
>   =fixAliasThis     when a symbol is resolved, check alias this 
> scope before going to upper scopes
>   =intpromote       fix integral promotions for unary + - ~ 
> operators
>   =dtorfields       destruct fields of partially constructed 
> objects
>   =rvaluerefparam   enable rvalue arguments to ref parameters
>   =nosharedaccess   disable access to shared memory objects
>
> [...]

Walter and I discussed this last week.

I think the right way to nudge D programmers to transition to 
where we can turn -preview into -revert is to issue deprecation 
messages for a while. Nothing like a noisy build to get people to 
file issues on github (or even better, PRs) to get this fixed.

I expect the annoying messages to happen soon. Then we have to 
decide on how long of a period is appropriate to start break 
builds.