Default initialization no longer a thing

[Salih Dincer]

On Tuesday, 24 October 2023 at 15:39:09 UTC, Hipreme wrote:
> The only problem I ever had with D was float being initialized 
> to nan instead of 0. This has been talked a lot of times now. 
> If you read the post from Sonke, you can see that D is not 
> being how simple it was from before from the addition of lot of 
> keywords: `pure`, `nothrow`,  `@nogc`, `scope`, `return`. I 
> don't want any more verbosity than that, so all hail default 
> initialization :D

I don't like using so many attributes either. Fortunately, your 
code usually works even when you don't use it :)

On Tuesday, 24 October 2023 at 01:35:16 UTC, deadalnix wrote:
> @disable this plain doesn't work. It prevent things in some 
> cases, but utltimately fails to enforce the invariant it sets 
> out to enforce.

The default constructor doesn't always work the way I want. Let's 
talk some code. Test1 and test2 are ok but the third one is 
something I came across recently:

```d
void main()
{
     string data;
     assert(data is null);

     /** TEST 1 **/
     struct String
     {
         string data;
     }

     String s;
     assert(s.data is null);

     auto s2 = String();
     assert(s2.data is null);

     /** TEST 2 **/
     struct Ztring
     {
         string data;

         this(string data)
         {
             this.data = data;
         }
    }

     Ztring z;
     assert(z.data is null);

     auto z2 = Ztring("D");
     assert(!(z2.data is null));

     /** TEST 3 **/
     struct Foo
     {
         int[] data;

         this(int[] data)
         {
             this.data = data;
             if(this.data.capacity < 4)
             {
                 this.data.length = 20;
             }
         }
     }
     auto l = Foo([1, 2, 3]);
     assert(l.data.capacity > 4);
}
```

I don't want my code to run with the default feature, but it 
shouldn't take any constructor parameters either. What I want is 
to increase the capacity of one of the members at compile time 
while it is initialized.

SDB at 79