Array-wise expressions and range checking

[Alexander]

Opened the issue 
http://d.puremagic.com/issues/show_bug.cgi?id=10384

Thank you!

On Sunday, 16 June 2013 at 09:35:23 UTC, Jonathan M Davis wrote:
> On Sunday, June 16, 2013 11:09:27 Alexander wrote:
>> Hello,
>> 
>> I'm reading "The D programming language", part "4.1.7 
>> Array-wise
>> Expressions".
>> 
>> It states that
>> 
>> "The effect of an array-wise expression is that of a loop
>> assigning each element of the
>> left-hand side in turn with the corresponding index of the
>> right-hand side. For example,
>> the assignment
>> 
>> auto a = [1.0, 2.5, 3.6];
>> auto b = [4.5, 5.5, 1.4];
>> auto c = new double[3];
>> c[] += 4 * a[] + b[];
>> 
>> is the same as
>> 
>> foreach (i; 0 .. c.length) {
>>      c[i] += 4 * a[i] + b[i];
>> }"
>
> Yeah, but as you failed to set any of c's elements to anything 
> first, and
> they're default initialized to NaN, and all math done on NaN 
> results in NaN,
> so none of c's elements will have changed in your example.
>
>> So I assume that the following code should generate runtime
>> exception during evaluation of c[2] = b[2] + a[2], but it 
>> doesn't
>> happen.
>>
>> auto b = [1, 2];
>> auto a = [2, 3, 4];
>> int c [] = new int[3];
>> c[] = b[] + a[];
>> return c;
>> 
>> Is it an intended behaviour or a compiler bug?
>
> That does look like a compiler bug. It should throw a 
> RangeError, because a
> and b have different lengths, but it isn't. Please report it:
>
> http://d.puremagic.com/issues
>
> - Jonathan M Davis