Stop numeric array key typecasting

[kkmuffme]

Description

Currently, PHP will automatically convert some int-like strings to int when used as array keys.

1. this can lead to unexpected behavior, depending on the array keys used (since some will get typecast, while others won't, even though both would pass is_numeric())

2. this adds overhead for type juggling on all array operations, since values need to be type juggled

This has been discussed in #9029

I think it would make sense to create an RFC to stop doing this with PHP 8.5 (I don't have permission, otherwise I would have done that already)

Since most people are unaware that this happens in the first place, the impact would probably not be too big, but it is definitely a breaking change.

[nielsdos]

Since most people are unaware that this happens in the first place

Are you sure about that?

the impact would probably not be too big, but it is definitely a breaking change.

I think the impact would be massive.

This indeed requires an RFC. But before you do that, it's probably wise to send an email to the mailing list to see how people will respond. After positive response, you can proceed with an RFC as outlined in https://wiki.php.net/rfc/howto

[iluuu1994]

I know this is categorized as a feature, but I have argued many times that issues like this just don't belong in the bug tracker, they belong in the mailing list. An RFC is incredibly likely to fail due to massive BC breakage, so time investment is not worthwhile. If you could demonstrate near-consensus on the mailing list, it might be another story.