On Tuesday, 22 November 2022 at 21:00:58 UTC, []() {}() wrote:
"Being able to declare a “friend” that is somewhere in some other
file runs against notions of encapsulation." (This is the
motivation for that article it seems).
I completely disagree with the assertion.
C++ Friend notion does not, not by any means, run against the
notion of encapsulation.
Sure, it expands the perimeter (i.e. it puts a door in the wall).
But, and this is my point, there is a guard standing at the door.
And that guard knows who has been authorised to pass through it.
The encapsulation remains. Only its perimeter has been expanded.
One could argue that D's approach is just that. It expands the
perimeter to the module level. But there's no guard at the door
in D.
Surely, this 'let anyone pass through' design, decreases
encapsulation? How could it possibly increase encapsulation, as
claimed, by the author of that article?
If there were a means in the language for controlled sharing
within a module, *that* would increase encapsulation.
