On Thursday, 6 August 2015 at 21:18:13 UTC, Steven Schveighoffer
wrote:
On 8/6/15 4:11 PM, Xiaoxi wrote:
On Thursday, 6 August 2015 at 19:55:20 UTC, Steven
Schveighoffer wrote:
On 8/4/15 4:54 PM, Steven Schveighoffer wrote:
How complete is the dip25 implementation?
For example, should this be expected to be an error?
struct S
{
int[5] x;
auto foo() { return x[];}
}
I'll note, that dmd 2.067.0 with -dip25 considered this an
error, head
does not. Adding a 'return' to the foo attributes fixes it
in 2.067,
but...
auto getS()
{
S s;
return s.foo();
}
does not error in either version, even with the return
attribute.
Anyone? Is this a bug or not?
why is it related to dip25? slices uses pointers not ref?
I think it's because the 'this' is implicitly ref.
I'm not sure why that would matter though, since you're returning
a dynamic array in foo - and thus in getS - so there is no ref
involved. It's unsafe, because that dynamic array is a slice of a
static array, but no ref is being returned - and no ref is being
passed in - so DIP 25 shouldn't apply.
If dip25 just throws its hands up on slicing, it has a problem
I think.
https://issues.dlang.org/show_bug.cgi?id=8838
On a related note, it would be great if we didn't have implicit
slicing of static arrays, but I expect that that boat of doom has
long since sailed... :(
In any case, 2.067 complained about it with -dip25, and didn't
without, so it seems related.
Well, DIP 25 itself says nothing about arrays at all, let alone
the slicing of static arrays. So, I don't know why 2.067 would
have given an error like it does. My first guess would be that it
was a bug in its implementation of -dip25, but I don't know.
- Jonathan M Davis
