Re: RFC: Trait expects interface

On 06/01/2022 23:53, Robert Korulczyk wrote:

But there is no easy way to say "FooTrait::someMethod() is implementation of FooInterface::someMethod()" that PHP and SCA will understand. And I think this proposal handles this quite well

I'm not convinced it does, actually. Consider the following trait: trait PropertyCount {

    public function count(): int {
        return count(get_object_vars($this));
    }

} This trait CAN be used to implement the built-in Countable interface, and it might be useful to label it as such; but does it really make sense to say that classes MUST implement that interface? Even if we put it as a requirement, we can't guarantee that the class will actually use the trait's implementation of the interface, because this would still be valid: class Foo implements Countable {

    private $whatever;

    use PropertyCount {
        count as getPropertyCount;
    }

    public function count(): int {
        return 0;
    }

} It feels like this use case would work better with an annotation like /** @can-implement Countable */ since it is really just documentation about possible uses. Regards, -- Rowan Tommins [IMSoP]