[libcxx-commits] [libcxx] [libcxx] Fix ODR violation in iostream. (PR #132125)

[A. Jiang via libcxx-commits]

================
@@ -250,6 +250,8 @@ _LIBCPP_BEGIN_NAMESPACE_STD
 
 typedef ptrdiff_t streamsize;
 
+struct _LIBCPP_HIDE_FROM_ABI uninitialized_ios{};
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frederick-vs-ja wrote:

This type should have an __ugly name. And perhaps it should have an explicit default constructor.
```suggestion
struct __uninitialized_ios_tag {
  explicit __uninitialized_ios_tag() = default;
};
```

https://github.com/llvm/llvm-project/pull/132125