CTFE for array / string / slice operations, constant propagation and bug detection at compile time

[Paul Backus]

On Saturday, 13 May 2023 at 19:21:30 UTC, Cecil Ward wrote:
> Would it be a nightmare to implement CTFE for arrays, slices 
> and strings? Optimisation of basic operations on these types, 
> in respect of concatenation, slicing and many more operations 
> would be extremely welcome. Would there possibly be a chance to 
> catch many bugs at compile-time?

As a point of comparison, it looks like neither gcc nor clang 
catch this kind of error in C code, even with every relevant 
warning flag I could find enabled:

https://godbolt.org/z/r5Tahe5YW

I'm not an expert, but my guess would be that if neither clang 
nor gcc implement this check, it's probably at least a little 
tricky to do.