Why do private member variables behaved like protected in the same module when creating deriving class?

[unprotected-entity]

On Sunday, 28 October 2018 at 15:47:15 UTC, Stanislav Blinov 
wrote:
> On Sunday, 28 October 2018 at 15:41:47 UTC, Neia Neutuladh 
> wrote:
>
>> In D, x is private to C and any types or functions defined in 
>> the same module.
>
> ...and can be accessed via reflection (.tupleof). </Pedantry>

Whenver that statement comes up, it needs to be mentioned, yet 
again, that access modifiers are not a 'security' feature.

They "are a convenient design constraint, to help us structure 
our applications properly." - and yes, they are convenient within 
a module too (unless your module doesn't care about them - cause 
then they're completely useless).

Using reflection to explicitly break open something, is not the 
same as leaving it completely open in the first place (within a 
module, where that is always the case).