Is it a bug that a parent class that access its own private members from derived classes gets deprecation warning?

[bauss]

On Monday, 9 April 2018 at 17:05:45 UTC, martin wrote:
> On Sunday, 8 April 2018 at 13:00:02 UTC, bauss wrote:
>> I think it's better demonstrated like this, because to me the 
>> behavior makes no sense.
>>
>> Especially since you can just cast "Bar" to "Foo" and then 
>> you're allowed to do it.
>>
>> Since we're inside Foo then it shouldn't care whether "_baz" 
>> is private or not.
>>
>> I could understand if the function was located within Bar, but 
>> it's not.
>>
>> It's perfectly normal in other languages that supports classes 
>> to access private members of parent's as long as you're within 
>> the parent's encapsulation.
>>
>> // a.d
>> module a;
>>
>> class Foo
>> {
>> 	private:
>> 	bool _baz;
>> 	
>> 	public:
>> 	void handleBar(T : Foo)(T[] foos)
>> 	{
>> 		foreach (child; foos)
>> 		{
>> 			child._baz = true; // Not ok.
>> 			(cast(Foo)child)._baz = true; // Ok.
>> 		}
>> 	}
>> }
>>
>> // b.d
>> module b;
>>
>> import a;
>>
>> class Bar : Foo
>> {
>> 	
>> }
>>
>> // main.d
>>
>> module main;
>>
>> import b;
>>
>> void main()
>> {
>> 	auto bars = [new Bar, new Bar];
>> 	auto bar = new Bar;
>> 	bar.handleBar(bars);
>> }
>
> Actually, this behaves as i would expect.
> `_baz` is a private member of Foo (to be precise: it belongs to 
> module `a`)
> in handleBar(), you iterate `Bar[]` - which is in module `b`.
> By casting it to Foo, you are accessing the wanted module (`a`) 
> again.

but handleBar() is in a.

This behavior is allowed in ex. C#