nit: Use nil pointer pattern to check for interface compliance.

[DimitrisJim]

Description

Reference: #3437 (comment)

To use a consistent style between creating an empty struct and taking its reference vs. casting a nil pointer to the type.

For types implementing interfaces using value receivers this works in exactly the same way since a pointer to that type is also considered as implementing the interface.

I'm hopeful I got most of them.

closes: #XXXX

Commit Message / Changelog Entry

nit: Use nil pointer pattern to check for interface compliance.

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[DimitrisJim]

I'd be happy to revert the changes on types implementing interfaces using value receivers if it generally gives the impression (unsure) they must be used as pointers.

[chatton]

I think the nil version is more efficient, but the gains here would be so inconsequential that I think the decision made should be one that favours readability over performance.

I personally find the struct literal syntax more readable/intuitive, however I don't feel that strongly about it. Consistency is more important to me than the actual style we choose.

Happy to go forward with this style if that is the preference people have!

[crodriguezvega]

Nice work, @DimitrisJim. :)

[crodriguezvega]

Nice that you grouped all these together. :)