Why does this code only work with `std.conv.to` whilst not with `cast`?

[matheus]

On Sunday, 8 January 2023 at 12:39:37 UTC, thebluepandabear wrote:
> ...
> The `foreach` worked for that case since `bark` is a method of 
> `IDog`. `update` is not so a conversion to `Button[]` is needed.
>

In that case, you could do a casting like this:

import std.stdio, std.conv;

interface IDog {
     void bark();
}

class Dog: IDog{
     string s;
     this(string _s){s = _s;}
     void bark(){writeln(s);}
     void update(string _s){ s ~= " - " ~ _s; }
}

class List{
     IDog[] dogs;
     void add(T)(T d){ dogs ~= d;  }
}

void main(){
     auto d1 = new Dog("meaw!");
     auto d2 = new Dog("wof!");
     auto l = new List();
     l.add(d1);
     l.add(d2);

     foreach(i,d; l.dogs){ // I'm using 'i' just to show each 
update.
         (cast(Dog)d).update(to!string(i));
         d.bark();
     }
}

Prints:

meaw! - 0
wof! - 1

Matheus.