Re: #[Deprecated] Attribute

On Tue, May 27, 2025 at 9:41 PM Ben Ramsey <ramsey@php.net> wrote: > > Last night, I identified a need for #[Deprecated] on a userland > class in > one of my libraries, but I had to settle on @deprecated for the > widest > range of compatibility. > > Has there been anymore thought on putting together an implementation for > this? I’m happy to draft an RFC if someone is able to help with the > implementation. I don’t understand the complexities around the > implementation, but is this something that could make it into 8.5, provided > an RFC vote passes? > > Cheers, > Ben > > I'd be willing to work on the implementation, but what I'm wondering is what exactly it would mean to deprecate a class. Without a clear idea of the goal, I didn't include this in https://news-web.php.net/php.internals/127305 even though I had considered it. Would a deprecated class * Emit warnings when constructed? Just deprecate the constructor, https://3v4l.org/DNrqm * Emit warnings when used as a type? But we allow types to include classes that don't exist (https://3v4l.org/pdkbv) so needing to look up the types that are declared to emit warnings (rather than just when used to verify that the type is respected) would presumably have a performance impact. * Emit warnings when extended? I suggested that in my email a few weeks ago, and when I have time I was going to look into that - I was thinking something like #[\WillBeFinal] that would work for classes, methods, properties, and constants, and would emit warnings just like #[\Deprecated] but not when a method is called or a constant is used, just when things are overridden What were you thinking in terms of desired semantics? --Daniel