Why is D unpopular

[Paul Backus]

On Monday, 13 June 2022 at 08:44:59 UTC, bauss wrote:
> On Monday, 13 June 2022 at 08:07:05 UTC, Mike Parker wrote:
>>
>> But why should that compile? You're trying to manipulate `_c` 
>> through an instance of `Bar`. It's not visible in any `Bar`, 
>> ever, so why should it be visible here? It has to be gotten at 
>> through the interface of `Foo`.
>
> Because I'm in the module of a, _c is a member if Foo, Foo is 
> in a.
>
> Thus _c should be accessible within a regardless of whether 
> it's public within the b module or not.

`_c` is accessible; you just have to use the syntax 
`child.Foo._c` to access it. This is documented in the language 
spec:

> Members of a base class can be accessed by prepending the name 
> of the base class followed by a dot

https://dlang.org/spec/class.html#fields

This is necessary because D allows you to define fields with the 
same name in a base class and its derived class; for example:


```
class Base
{
     int x = 123;
}

class Derived : Base
{
     int x = 456;
}

void main()
{
     auto instance = new Derived;
     assert(instance.x == 456);
     assert(instance.Base.x == 123);
}
```