On 8/19/05, Jonathan Wakely <[EMAIL PROTECTED]> wrote:
> WU Yongwei wrote:
> > Well, I see this in the gcc error message. Can someone here kindly
> > point to me which part of the Standard specified this behaviour? I
> > thought it should be in 5.3.4, but was not able to find the words
> > there.
[snipped]
> This is OK, and default initialises the array, which default initialises
> each element (8.5/5)
>
>int* i = new int[5]();
>
> but this is not OK:
>
>int* i = new int[5](23);
>
> because it is not valid to initialise an array like this:
>
>typedef int (five_ints)[5];
>five_ints i(23);
>
> this gives:
>
> array_init.cc:8: error: cannot initialize arrays using this syntax
This sounds reasonable. The only problem is that it does not
constitute proof. It is complete OK if the standard disallowed `int
a[5](23)' while allowing `new int[5](23)', just as older GCC did.
On 8/19/05, Alisdair Meredith <[EMAIL PROTECTED]> wrote:
> WU Yongwei wrote:
>
> > Well, I see this in the gcc error message. Can someone here kindly
> > point to me which part of the Standard specified this behaviour? I
> > thought it should be in 5.3.4, but was not able to find the words
> > there.
> >
> > By the way, anyone knows the rationale of this behaviour?
>
> It is not explicitly forbidden. Rather, there is no syntax defined that
> would enable it (so it is implicitly forbidden)
My observations. According to 5.3.4, an expression like `new
int[5](23)' is well-formed. Just that no semantics are formally
defined for it.
The behaviour might be OK, but the message seems a little misleading.
Would something like `cannot specify initializer for arrays' be better
since it really has little to do with `array new'?
Also, the trends of gcc removing existing `extensions' are a little
worrisome. IMHO, the extension should be allowed and a warning in the
case of `-W' or `-ansi' should be issued.
Best regards,
Yongwei
