[libcxx-commits] [PATCH] D81133: Use allocator_traits to consistently allocate/deallocate/construct/destroy objects in std::any

[Marshall Clow via Phabricator via libcxx-commits]

mclow.lists marked an inline comment as done.
mclow.lists added inline comments.


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Comment at: libcxx/include/any:370
     static _Tp& __create(any & __dest, _Args&&... __args) {
-        _Tp* __ret = ::new (static_cast<void*>(&__dest.__s.__buf)) _Tp(_VSTD::forward<_Args>(__args)...);
+        typedef allocator<_Tp> _Alloc;
+        typedef allocator_traits<_Alloc> _ATraits;
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EricWF wrote:
> Can `std::allocator` have behavior that observably differs from this code? (which is just the default std::allocator inlined).
Sure. A user-specialization of `std::allocator` can do most anything, as long as it actually constructs the object as well. 

Register it in a global registry, for example.


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  https://reviews.llvm.org/D81133/new/

https://reviews.llvm.org/D81133