array of elements of various sybtypes

[spir]

On 01/26/2011 07:23 PM, Steven Schveighoffer wrote:
> 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];

Nope, refused for the same reason (tried to construct [t1,t2] before casting it).

Denis
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