Closure::bindTo Throwable instead of warning when passing object other class

Description:

Currently, when binding a new object to Closure, which is an object of a different class, a "warning" is logged in the log, but the method itself has no effect, which can be confusing.

It seems to me better to add Throwable in such a scenario, it will make it easier to handle the case.

The following code:

<?php

class SomeClass
{
    public function testMethod() {
        echo 123;
    }
}

class OtherClass
{
    public function testMethod() {
        echo 234;
    }
}

$a = new SomeClass();
$b = new OtherClass();

$closure = Closure::fromCallable([$a, 'testMethod']);

try {
    $closure->bindTo($b);
} catch (Throwable $e) {
    echo 'Oh, sorry u cannot do it!';
    return;
}

$closure();

Resulted:

Warning: Cannot bind method SomeClass::testMethod() to object of class OtherClass in /in/VgKd4 on line 23
123

Expected:

Oh, sorry u cannot do it!

Workaround:

As it stands, to be able to handle such a scenario you need to use Reflection as follows:

$reflection = new ReflectionFunction($closure);
$oldThis = $reflection->getClosureThis();
if ($oldThis && $oldThis::class === $b::class) {
    $closure->bindTo($b);
} else {
    echo 'Oh, sorry u cannot do it!';
}

Of course, this code can be simplified, but a simple try/catch is a much better solution.

Especially since I assume that the parser will check again if the object is of the same class when executes bindTo()

PHP Version

PHP 8.2.6

Operating System

Linux

Start with the provided Closure::fromCallable() and bindTo() reproducer, then inspect the Closure::bindTo entry point and current warning behavior. Done means binding an object of an incompatible class is catchable as Throwable, with coverage for the shown case and no regression for valid bindings.