Request for Comment assert(__ctfe)

[Petar]

On Sunday, 5 April 2020 at 18:30:25 UTC, Stefan Koch wrote:
> On Sunday, 5 April 2020 at 18:25:10 UTC, Petar Kirov 
> [ZombineDev] wrote:
>> On Sunday, 5 April 2020 at 12:11:23 UTC, Stefan Koch wrote:
>>> [...]
>>
>> Another, more radical and interesting option is to not perform 
>> codegen unless it's actually necessary. Instead of 
>> blacklisting `@ctfe` or `assert(__ctfe)` functions, have a 
>> whitelist of what functions are allowed to codegen-ed.
>>
>> [...]
>
> Seems like you are reading my mind.
> Indeed this is one of next steps ...
> assert(__ctfe) did not break a single package, in out CI!
> Therefore I do now have enough confidence in crawling the 
> dynamic dependencies outwards from the entry point and exported 
> functions.
>
> That however is for the future and will require me to do some 
> theoretical work, in order to proof to myself that it actually 
> is feasible and won't end up in a nightmare of subtly broken 
> builds.

Great! Perhaps we should write a DIP to specify the semantics of 
such a lazy compilation model? An even more extreme option would 
be to not perform semantic analysis on non-`export`-ed functions. 
This should bring some really high gains, though it would be the 
trickiest to adopt option for users.