Why is D unpopular, redux.

[mw]

On Saturday, 28 May 2022 at 19:30:42 UTC, Ola Fosheim Grøstad 
wrote:
> On Saturday, 28 May 2022 at 18:15:10 UTC, Ola Fosheim Grøstad 
> wrote:
>> On Saturday, 28 May 2022 at 17:32:04 UTC, IGotD- wrote:
>>> Folding in C++ is perhaps "powerful" but at the same time 
>>> unreadable.
>>
>> I find it to be quite limited, but also confusing for the 
>> reader:
>
> Two nested folds (nested loops):
>
>
> ```
> template<int... as, int... bs>
> void f(std::integer_sequence<int, as...> 
> _1,std::integer_sequence<int, bs...> _2) {
>
>     std::cout << ([](auto x){ return ((bs+x) * ...);}(as) + 
> ...) << std::endl;
>
> }
>
>
> int main()
> {
>     f(std::integer_sequence<int,1,2,4>{}, 
> std::integer_sequence<int,1,-1>{});
>     return 0;
> }
> ```
>
> How many seconds do you need to understand what goes on?
>
> (Maybe it would be better to just implement Lisp.)


Wow, haven't looked at C++ for decades, it has advanced this far? 
Truely marvelous ;-) a vivid testimony of Greenspun's tenth rule:

Any sufficiently complicated C or Fortran program contains an ad 
hoc, informally-specified, bug-ridden, slow implementation of 
half of Common Lisp.


(just plug in C++ here :-)


https://en.m.wikipedia.org/wiki/Greenspun%27s_tenth_rule