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<?php class B { protected function c() { return 1; } } class C1 extends B { function f(B $x) { return $x->c(); } } class C2 extends B { protected function c() { return 2; } } var_dump((new C1)->f(new C2));
Output for 8.1.34, 8.2.0 - 8.2.32, 8.3.0 - 8.3.33, 8.4.1 - 8.4.24, 8.5.0 - 8.5.9
int(2)

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