Using closure in function scope to make "real" private class members

[zjh]

On Tuesday, 7 June 2022 at 09:09:52 UTC, zjh wrote:

> `Class encapsulation` is a must for ordinary `c++ people`!

C++ developers are used to `class encapsulation`.
Moreover, this kind of `"minimal" encapsulation`, the "c++" 
developers, has been deeply rooted in the `hearts` of the people, 
and no one complains,like it doesn't exist!
But in `'d'`, there is no `'class encapsulation' `, which is 
unthinkable!