Re: [RFC] Allow Reassignment of Promoted Readonly Properties in Constructor

Hi Rob, Le mar. 3 févr. 2026 à 09:50, Rob Landers <rob@bottled.codes> a écrit : > On Mon, Feb 2, 2026, at 22:14, Nicolas Grekas wrote: > > Hi Marco, > > Le lun. 2 févr. 2026 à 11:54, Marco Pivetta <ocramius@gmail.com> a écrit : > > Hey Nicolas, > > > On Thu, 22 Jan 2026 at 16:34, Nicolas Grekas <nicolas.grekas+php@gmail.com> > wrote: > > Dear all, > > Here is a new RFC for you to consider: > https://wiki.php.net/rfc/promoted_readonly_constructor_reassign > > > > What happens if one calls $obj->__construct(1, 2, 3) (on an > already > instantiated $obj) in the context of this patch? > > > Thanks for asking, I didn't think about this. This made me also think > about ReflectionClass::newInstanceWithoutConstructor(). > I clarified this in the RFC, see "Direct __construct() Calls Cannot Bypass > Readonly" and "Reflection: Objects Created Without Constructor". > Patch and PR updated also if anyone wants to run some code where this RFC > can be played with. > > Cheers, > Nicolas > > > Hi Nicolas, > > Under "Child Classes Can Reassign Parent Properties": this feels like a > major footgun. Calling parent::__construct() won't allow a reset (per the > rules of calling a constructor directly); which would completely break > inheritance... but then in the examples it says that calling a constructor > directly can reset it -- but you can't? > > This feels really inconsistent to me. > > — Rob > Yes, the text was ambiguous. The implementation allows parent::__construct() during the initial construction (normal inheritance), and only blocks explicit __construct() calls after construction completed. I’ve clarified this in the RFC. Nicolas