[PATCH] D47607: [libcxx] Almost fix some UB in <map> and <unordered_map>

[Richard Smith - zygoloid via Phabricator via cfe-commits]

rsmith added inline comments.


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Comment at: libcxx/include/map:617
 template <class _Key, class _Tp>
 union __value_type
 {
----------------
This doesn't need to be a union any more; change to class?


================
Comment at: libcxx/include/map:633
+#if _LIBCPP_STD_VER > 14
+        return _VSTD::launder(this)->__cc;
+#else
----------------
Formally this should be `return *_VSTD::launder(&this->__cc);`, because `this` must already point to an in-lifetime object or the member function call would have been invalid.


Repository:
  rCXX libc++

https://reviews.llvm.org/D47607