Best way to reference an array in a child class...

[captain_fid]

On Friday, 7 March 2014 at 13:57:31 UTC, Steven Schveighoffer 
wrote:
> On Thu, 06 Mar 2014 17:44:09 -0500, captain_fid 
> <bell.hue at gmail.com> wrote:
>
>>
>>>>   this() {items = [ {10, "first"}, {20, "second"}];}
>>
>> strangely enough, when modeling this the first time (using 
>> items as a class) and 'new item() syntax) there was no real 
>> issue.
>>
>> I thought using a static array of structs in the children 
>> would be more efficient when instantiating the objects. Never 
>> mind whether its true or not - Speed isn't a really a concern, 
>> learning is.
>
> I missed this the first time. That is a difference between my 
> code and your code. Mine creates a new instance of an array on 
> *object* initialization, yours creates ONE instance of an 
> array, that all objects share.
>
> This is not necessarily a good thing. Because you've created a 
> mutable version of the array. I believe it is initialized on 
> startup from the heap.
>
> One really bad thing is, the same array is used if you 
> initialize from multiple threads. And it's mutable, making it 
> implicitly shared even though it shouldn't be. You should make 
> the array immutable and static, or else initialize it in the 
> constructor. I don't know your use case, so it's hard to say 
> what you should do.
>
> -Steve

>> I don't know your use case, so it's hard to say what you 
>> should do.

Steve, I don't think I know my use case -- So it's not you. I'm 
attempting to model hardware, where 'items' in this case are an 
static array of registers. Single threaded (for now). Mainly, 
this a learning opportunity to get a better understanding of D 
for future comparison (vs. C++).

> This is not necessarily a good thing. Because you've created a 
> mutable version of the array. I believe it is initialized on 
> startup from the heap.

Lot to learn. I understand initialized from the heap, but do you 
mean at program startup, or object instantiation? If program, I 
would have expected that with __gshared (globals) only, not with 
this.

> One really bad thing is, the same array is used if you 
> initialize from multiple threads. And it's mutable, making it 
> implicitly shared even though it shouldn't be. You should make 
> the array immutable and static, or else initialize it in the 
> constructor.

I appreciate your suggestions and the patience.