[php-src] Issue #7778: Enum could not be converted to string with \array_intersect

Issue: https://github.com/php/php-src/issues/7778 Comment Author: damianwadley Related is that there was a [deliberate decision](https://wiki.php.net/rfc/enumerations#auto-scalar_conversion) to not support automatically converting _backed_ enums to their backed type for the time being. As mentioned, implementing that will come in a future RFC after enums have settled into common usage. > I think at this point we'd be better off adding a new > array_intersect alternative that uses strict comparison instead. Sorting would still be required to reach O(n log n) efficiency that the various array comparison functions offer. Using only equality would mean settling for the naive O(n^2) algorithm - which could also be trivially implemented in userland if there was a need to work with arrays containing unsortable items like enums. Now, what to do with this issue? I'm not sure. On the old tracker I'd resolve as Suspended, but those did have a tendency to get lost and forgotten over time. At the very least this isn't actionable now or in the foreseeable future, and there is the fact that array_intersect and enums are actually behaving as intended...