Adding a new design constraint to D

[Max Samukha]

On Tuesday, 14 June 2022 at 13:49:30 UTC, Ola Fosheim Grøstad 
wrote:

>
> It isn't necessarily through a different path unless you think 
> that Bar is cloaking Foo, basically redoing everything that is 
> Foo.

D encourages me to think about it as being similar to 'alias 
this', which seems to behave differently:

```d
module a;

import b;

struct Foo
{
     private int _c;
}

void foo(Bar b)
{
     b._c = 1; // passes, to Mike's and my surprise
}

void main()
{
}
```
```d
module b;

import a;

struct Bar
{
     Foo foo;
     alias foo this;
}
```