How do I _really_ implement opApply?

[Vladimir Panteleev]

On Wednesday, 30 November 2022 at 01:30:03 UTC, Steven 
Schveighoffer wrote:
> On 11/29/22 7:50 PM, WebFreak001 wrote:
>
>> (note: I don't want to use a template, this way of writing it 
>> has the advantage that the compiler checks all different code 
>> paths for errors, so the errors aren't delayed until someone 
>> actually tries to iterate over my data structure)
>
> 1. use the template
> 2. use a unittest to prove they all compile.

+1. I use this pattern often:

https://github.com/CyberShadow/ae/blob/86b016fd258ebc26f0da3239a6332c4ebecd3215/utils/graphics/libpng.d#L716-L721

https://github.com/CyberShadow/ae/blob/86b016fd258ebc26f0da3239a6332c4ebecd3215/utils/math/combinatorics.d#L220-L222