Sealed classes - would you want them in D?

[bachmeier]

On Saturday, 12 May 2018 at 06:35:55 UTC, KingJoffrey wrote:

> Come on, your code example misses my point completely.
>
> Take this program below, for example, and tell me that class 
> encapsulation is not broken in D:
>
> ===============================
> module test;
>
> import std.stdio : writeln;
>
> void main()
> {
>     Person p = new Person("King Joffrey");
>
>     writeln(p.getName); // I designed my class to return this.
>     writeln(p._name); // But D can bypass your intention 
> completely.
>
>     p._name = "New King"; // even worse, D can nominate another 
> king.
>     writeln(p._name);
> }

I think I'm missing something. Why is it a problem that you can 
do this? How do other languages prevent you from doing it?