Re: ARRAY_UNIQUE_IDENTICAL option

> To solve this, I propose adding an ARRAY_UNIQUE_IDENTICAL option that > can be passed to array_uniques $flags which uses identical operator > (===) semantics. Internally it uses a new hashmap that allows using > arbitrary PHP values as keys to efficiently remove duplicates. This is > slightly over-engineered for this use case. However, this data > structure will be required for implementing ADTs to deduplicate > instances with the same values. This hashmap is a heavily minimized > version of the teds extensions StrictHashMap [1]. As a regular developer, I look from the usage side, not from the implementation side. From such perspective, remembering that filtering unique enums requires this exact flag is somewhat "dirty": on the surface, nothing tells that enums are non-comparable. You will have to memorize yet another PHP quirk, or be able to build a logical chain: - enums are non-comparable by default - enums have no default string value (if not baked by a string) - array_unique internally sorts an array - default flag for array_unique compares the string representations of its items - thus it won't work for enums in a general case This requires deeper knowledge of PHP, which is for sure a valuable skill, but not as wide-spread as we would like to. Most of the devs will first try to use array_unique() with the default flag, perhaps not even knowing about flags existence. Each usage of such a flag will not reveal intent by itself and at least will require a comment for readable codebases. Perhaps an alternative idea is to provide a default string value for enums which are not baked, Nikolas had already brought up this idea earlier.