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Date: Thu, 19 Aug 2010 17:04:26 +0300
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Subject: Re: [PHP-DEV] inheritance check too strict?
From: ionut.g.stan@gmail.com ("Ionut G. Stan")

On 19/Aug/10 4:16 PM, Ryan Panning wrote:
> Nathan Rixham wrote:
>> what if Bar implements Foo, or Bar extends Foo - surely that should be
>> compatible given the inheritance chain.
>
> I ran into this exact issue and thought it was strange. Is there a
> reason this shouldn't be allowed?

It still breaks the interface:

class Parent
{
     public function foo(Foo $foo)
     {}
}

class Child
{
     public function foo(Bar $bar)
     {}
}

class Foo
{}

class Bar extends Foo
{}



All fine until here, but what if...



class Taz extends Foo.
{}


I can't call Child::foo() with an instance of Taz, but I can call 
Parent::foo() with such an instance. So, I can't use instances of Child 
wherever instances of Parent would be accepted.

-- 
Ionuț G. Stan  |  http://igstan.ro