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<?php interface DogFeeder { function feed(Dog $dog); } function feedChihuahua(DogFeeder $feeder) { $feeder->feed(new Chihuahua()); // this code is OK } class BulldogFeeder implements DogFeeder { function feed(Bulldog $dog) { } } feedChihuahua(new BulldogFeeder()); //
Output for 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
Fatal error: Could not check compatibility between BulldogFeeder::feed(Bulldog $dog) and DogFeeder::feed(Dog $dog), because class Dog is not available in /in/sULkI on line 14
Process exited with code 255.
Output for 7.1.26 - 7.1.33, 7.2.17 - 7.2.33, 7.3.0 - 7.3.33
Fatal error: Declaration of BulldogFeeder::feed(Bulldog $dog) must be compatible with DogFeeder::feed(Dog $dog) in /in/sULkI on line 12
Process exited with code 255.

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