[libcxx-commits] [libcxx] [libc++][unique_ptr] Implement LWG 4144: Disallow unique_ptr<T&, D> (PR #209018)

[Nikolas Klauser via libcxx-commits]

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@@ -100,6 +101,12 @@ inline const bool __can_dereference = false;
 template <class _Tp>
 inline const bool __can_dereference<_Tp, decltype((void)*std::declval<_Tp>())> = true;
 
+template <class _Tp, class = void>
+inline const bool __is_pointable = false;
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philnik777 wrote:

I'm not a huge fan of this name. Something more descriptive like `__can_be_pointed_to` or `__can_add_pointer`?

Also, can we write this as `!is_same<__add_pointer_t<_Tp>, _Tp>`?

I'd love to just write `requires { _Tp*; }` without giving this a name at all, but unfortunately we don't like in that world (yet).

https://github.com/llvm/llvm-project/pull/209018