[libc++] Use __is_array if the builtin is fixed

[philnik777]

No description provided.

[llvmbot]

@llvm/pr-subscribers-libcxx

Author: Nikolas Klauser (philnik777)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/93037.diff

1 Files Affected:

• (modified) libcxx/include/__type_traits/is_array.h (+2-3)

diff --git a/libcxx/include/__type_traits/is_array.h b/libcxx/include/__type_traits/is_array.h
index 5b0e0e6f46b81..dc23de28d2c63 100644
--- a/libcxx/include/__type_traits/is_array.h
+++ b/libcxx/include/__type_traits/is_array.h
@@ -19,9 +19,8 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-// TODO: Clang incorrectly reports that __is_array is true for T[0].
-//       Re-enable the branch once https://llvm.org/PR54705 is fixed.
-#if __has_builtin(__is_array) && 0
+#if __has_builtin(__is_array) &&                                                                                       \
+    (!defined(_LIBCPP_COMPILER_CLANG_BASED) || (defined(_LIBCPP_CLANG_VER) && _LIBCPP_CLANG_VER >= 1900))
 
 template <class _Tp>
 struct _LIBCPP_TEMPLATE_VIS is_array : _BoolConstant<__is_array(_Tp)> {};

[ldionne]

LGTM but this may require coordination with the Docker image to pull a fixed version of the clang nightly build.