[libcxx-commits] [PATCH] D130835: [libc++] Fix a hard error in `contiguous_iterator<NoOperatorArrowIter>`.

[Konstantin Varlamov via Phabricator via libcxx-commits]

var-const added inline comments.


================
Comment at: libcxx/include/__memory/pointer_traits.h:197
 template <class _Pointer, class = __enable_if_t<
-    !is_pointer<_Pointer>::value && !is_array<_Pointer>::value && !is_function<_Pointer>::value
+    _And<is_class<_Pointer>, _IsFancyPointer<_Pointer> >::value
 > >
----------------
This is more to start a discussion. Would it be easier to list what the `_Pointer` could be rather than what it should *not* be? Are there any other alternatives rather than a class that we would accept here?


================
Comment at: libcxx/include/__memory/pointer_traits.h:197
 template <class _Pointer, class = __enable_if_t<
-    !is_pointer<_Pointer>::value && !is_array<_Pointer>::value && !is_function<_Pointer>::value
+    _And<is_class<_Pointer>, _IsFancyPointer<_Pointer> >::value
 > >
----------------
var-const wrote:
> This is more to start a discussion. Would it be easier to list what the `_Pointer` could be rather than what it should *not* be? Are there any other alternatives rather than a class that we would accept here?
`_And` is necessary because `enable_if` doesn't short-circuit, so it would still try to evaluate `_IsFancyPointer` on e.g. an array, leading to a hard error when trying to instantiate `pointer_traits<array-type>`.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D130835/new/

https://reviews.llvm.org/D130835