std.v2020.algorithm etc[ WAS: Is run.d going to be expand for runtime and the phobos library?]

[Paul Backus]

On Monday, 22 June 2020 at 21:46:51 UTC, Andrei Alexandrescu 
wrote:
> On 6/22/20 12:50 PM, Paul Backus wrote:
>> 
>> The trick used for arrays does not only apply to function 
>> calls:
>> 
>>      const(int[]) a = [1, 2, 3];
>>      const(int)[] b = a; // compiles
>
> That's different - it's an implicit conversion.
>
>> IMHO the principled way to allow user-defined implicit 
>> conversions is...to allow user-defined implicit conversions. 
>> But iirc that's a can of worms Walter prefers not to open.
>
> What happens upon function calls is not an implicit conversion. 
> It's a forced type change.

So what you're saying is, it's even *less* principled than I 
thought? :)

Regardless, my broader point is that once we're open to the 
possibility of designing a new range API, all of this can be 
solved without any language changes by using an API that doesn't 
require mutation (i.e., tail()). Surely that's a better solution 
than implicitly inserting calls to arbitrary user-defined code 
every time someone passes an argument to a function.