array of elements of various sybtypes

[Steven Schveighoffer]

On Wed, 26 Jan 2011 12:27:37 -0500, spir <denis.spir at gmail.com> wrote:

> Hello,
>
> This fails:
>
> class T0 {}
> class T1 : T0 {}
> class T2 : T0 {}
>
> unittest {
>      auto t1 = new T1();
>      auto t2 = new T2();
>      T0[] ts = [t1, t2];
> }
>
> Error: cannot implicitly convert expression (t1) of type __trials__.T0  
> to __trials__.T2
> Error: cannot implicitly convert expression ([(__error),t2]) of type  
> T2[] to T0[]
>
> I guess it should be accepted due to explicite typing 'T0[]'. What do  
> you think? D first determines the type of the last element (always the  
> last one), here T2. Then, /ignoring/ the array's defined type, tries to  
> cast other elements to the same type T2. It should instead, I guess,  
> check all elements are compatible with the defined array type.
> An additional enigma is why the failing element t1 is said to be of  
> supertype T0 --which is also correct-- while it retained t2's exact type  
> T2. ???
>
> Anyway, is there a workaround?

auto ts = cast(T0[])[t1, t2];

-Steve