[libcxx-commits] [libcxx] [libc++] Fix failure with GCC 15 (#117319) (PR #117322)

[Louis Dionne via libcxx-commits]

================
@@ -25,7 +25,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if __has_builtin(__decay)
+#if __has_builtin(__decay) && !defined(_LIBCPP_COMPILER_GCC)
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ldionne wrote:

Ah, so do we need to do something like

```
template <class _Tp>
struct __decay_impl {
  using type = __builtin_decay_t(_Tp);
};

template <class _Tp>
using __decay_t = typename __decay_impl<_Tp>::type;
```

?

https://github.com/llvm/llvm-project/pull/117322