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<?php class Mammal { function mate(Mammal $with) { $class = substr(get_class($this), 1, -1) . substr(get_class($with), 1); eval("class $class extends Mammal {}"); return new $class; } } class Panda extends Mammal {} class Dolphin extends Mammal {} $mingmong = new Panda; $charles = new Dolphin; $charlimong = $mingmong->mate($charles); var_dump($charlimong);

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