I think it would make more sense for typed properties to exist first, and it so happens that there was a recent RFC for this: https://wiki.php.net/rfc/typed-properties. That RFC failed by a very small margin.
I would suggest you read through the discussions on the mailing list regarding that RFC for some common arguments to typing in PHP. On Wed, Nov 16, 2016 at 12:44 PM, Michael Morris <tendo...@gmail.com> wrote: > Perhaps it's time to revisit the idea of allowing variables to have their > types locked down. The keywords needed are already reserved. So... > > string $a = "hello"; > int $b = 5; > > Once declared this way the variable's type won't change unless it gets > unset. In normal mode PHP will coerce any assignment to the variable to the > desired type. If declare strict types is on then assigning the wrong type > to a variable would raise a type error. > > Note this would simplify one of the use cases of setters - insuring the > class member is of a valid type. > > The idea of function overloading reminded me of this. I'd consider being > able to do this sort of type lockdown to be prerequisite to having > overloaded functions. > > Since this approach is entirely opt in I don't think it would make the > language harder to learn. >
