Null references redux

[Max Samukha]

On Wed, 30 Sep 2009 18:26:20 +0300, Max Samukha <spambox at d-coding.com>
wrote:

>On Wed, 30 Sep 2009 08:53:57 -0400, bearophile
><bearophileHUGS at lycos.com> wrote:
>
>>If nonnull class references are added to D, then it can be good to add nonnull struct pointers too, to avoid similar bugs.
>>
>>(In C# for a struct you define a "default" one, that gets used by the compiler as the default one when the struct reference is null).
>>
>>Bye,
>>bearophile
>
>Don't get confused by 'new' in struct initializers. Structs in C# are
>value types. You can box them, use pointers to them in 'unsafe'
>context but you can't directly allocate them on heap. So there is no
>nullable references to structs. When you do:
>
>struct S
>{
>  public int x;
>}
>
>S s = new S(); // x is default initialized to 0

Ok. I have rechecked this one and it appears that you don't have to
initialize a struct if it is a POD (Microsoft names such structs
'unmanaged', of course) or you don't access fields that are
references. For example:

struct S
{
   public int x;
   public Object obj;
}

S s;
s.x = 1; // ok,  we can get away without initialization for now
s.obj.ToString(); // compile-time error