Zig vs D generics

[German Diago]

On Monday, 10 October 2022 at 07:30:38 UTC, Kagamin wrote:
>>In contrast, C++ code attempting to call non-constexpr 
>>functions (i.e. functions only accessible at run time) in a 
>>constexpr context (i.e. functions which are available both at 
>>compile time and run time) will give an error at the call site.
>
> Eh? So can C++ support an allocator that works both at compile 
> time and at run time? I use such allocator in my D code so it's 
> ctfeable.

Yes, it does, but it has limits 
https://www.cppstories.com/2021/constexpr-new-cpp20/

As for the comment about C++ code attemping to call non-constexpr 
functions. Careful with not marking functions constexpr. I used 
to think it was a hell of thing. But if you think of it, 
constexpr is part of the user contract. You could make a function 
non-ctfe by accident in D and break user code. C++ is explicit 
about it.