<?php
trait T {
abstract function foo(): string;
function bar(): string {
return $this->foo();
}
}
abstract class A {
use T;
}
/*
class B extends A {
// This fatals as expected
function foo() {
return 'some string';
}
}
*/
class C {
use T;
// This does not
function foo() {
return 'some string';
}
}
class D {
use T;
// This ALSO does not
function foo(): int {
return 3;
}
}
abstract class E {
use T;
// Nor this
function foo() {
return 'some thing';
}
}
(new D())->bar();
Fatal error: Declaration of C::foo() must be compatible with T::foo(): string in /in/OlOJg on line 28
Process exited with code 255.
Output for 8.3.5
Warning: PHP Startup: Unable to load dynamic library 'sodium.so' (tried: /usr/lib/php/8.3.5/modules/sodium.so (libsodium.so.23: cannot open shared object file: No such file or directory), /usr/lib/php/8.3.5/modules/sodium.so.so (/usr/lib/php/8.3.5/modules/sodium.so.so: cannot open shared object file: No such file or directory)) in Unknown on line 0
Fatal error: Declaration of C::foo() must be compatible with T::foo(): string in /in/OlOJg on line 28
Process exited with code 255.