TypeFunction example: ImplictConvTargets

[Stefan Koch]

On Tuesday, 6 October 2020 at 12:07:40 UTC, John Colvin wrote:
> On Tuesday, 6 October 2020 at 10:22:44 UTC, Stefan Koch wrote:
>> On Tuesday, 6 October 2020 at 01:12:01 UTC, Walter Bright 
>> wrote:
>>> [...]
>>
>> Okay let me show you the transitive dependencies of the "3 
>> liner" suggested by Andrei and executed by Paul Backus.
>>
>> [...]
>
> That implementation was *definitely* (and very obviously) not 
> created for simplicity. It can be done in way fewer lines than 
> that (and you know that, obviously).
>
> The argument to be made is "look how ridiculous this code has 
> to be to avoid some of the worst performance problems, look how 
> simple the type functions approach is and how much faster it 
> is", yes?

Yes that sums it up very well actually.
I am not good enough with recursive templates to simplify the 
implementation  without the risk of introducing bugs 
unfortunately.
Which is why I asked for others to provide code to compare this 
to.