[libcxx-commits] [PATCH] D72036: [libcxx] span: Cleanup includes

[Marshall Clow via Phabricator via libcxx-commits]

mclow.lists added inline comments.


================
Comment at: libcxx/include/span:148
+template <class _Tp, size_t _Sz>
+struct array;
 
----------------
miscco wrote:
> mclow.lists wrote:
> > Forward declaring `array` will lead to other problems down the road. 
> > Visibility problems. Which lead to ODR violations.
> > 
> I would disagree. It is essentially only used by the deduction guides. So to use it one has to already have array included.
> 
> I would say the other way is surprising as shown in the test, where the array header was not included but used.
> 
> That said I would not really make a stand Herr.
if you look in `<array>`, you will see the following declaration:
```
template <class _Tp, size_t _Size>
struct _LIBCPP_TEMPLATE_VIS array
```

Your forward declaration is different.

Also, for some definitions of `_LIBCPP_TEMPLATE_VIS`, it can only be on the //first // declaration of the template in any translation unit.  How would you enforce this?




Repository:
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CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D72036/new/

https://reviews.llvm.org/D72036