On 07/04/2013 06:43 PM, bearophile wrote:
> Ali Çehreli:
>
>> However, that is a confusing syntax because the right-hand side is not
>> the same type as the elements, which is dchar[3]. Perhaps D supports
>> it for C compatibility?
>>
>> It doesn't match the following. Here, the right-hand side is the same
>> as the element type:
>>
>> int[2] arr2 = 42;
>> assert(arr2 == [ 42, 42 ]);
>>
>> But this doesn't compile:
>>
>> char[3][5] arr = [ '.', '.', '.' ];
>>
>> Error: mismatched array lengths, 15 and 3
>>
>> I see that as a bug but can't be sure.
>
> In D char literals as 'x' or even string literals as "xx" are seen as
> instances of all the types of strings and chars, it's not a bug, it's a
> feature:
>
> void main() {
> char x1 = 'x';
> wchar x2 = 'x';
> dchar x3 = 'x';
> string s1 = "xx";
> wstring s2 = "xx";
> dstring s3 = "xx";
> }
>
>
> There is a way to specify the type of a string, so this gives errors:
>
> void main() {
> string s1 = "xx"d;
> string s2 = "xx"w;
> wstring s3 = "xx"d;
> }
>
> Bye,
> bearophile
Thanks for the refresher. My comment was about array initialization. We
can define an array by a value on the right-hand side that is the same
as the element types:
int[2] arr2 = 42;
assert(arr2 == [ 42, 42 ]);
Good: Every element has the value 42.
Now I have another array where the elements are of type int[3]:
int[3][2] arr = [ 10, 20, 30 ];
Error: mismatched array lengths, 6 and 3
Do you see the inconsistency? The element type is int[3] and the initial
value is [ 10, 20, 30 ]. However there is a compilation error.
Further, the code compiles even if I use a different type as the initial
value:
int[3][2] arr = 10;
I would expect that to be an error because the element type is not an
int but int[3]. We know that an int[3] can be initialized by 10 but a 10
should not be allowed to be used as an int[3].
That was my point.
Ali
