[PATCH] D28222: [libcxx] Re-implement LWG 2770 again: Fix tuple_size to work with structured bindings

[Richard Smith via Phabricator via cfe-commits]

rsmith accepted this revision.
rsmith added a comment.
This revision is now accepted and ready to land.

LGTM, but a minor simplification seems possible.



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Comment at: include/__tuple:32
 template <class _Tp>
-class _LIBCPP_TYPE_VIS_ONLY tuple_size<const _Tp>
-    : public __tuple_size_base_type<_Tp>::type {};
+class _LIBCPP_TYPE_VIS_ONLY tuple_size<__enable_if_tuple_size_imp<const _Tp, decltype(tuple_size<typename remove_cv<_Tp>::type>::value)>>
+    : public integral_constant<size_t, tuple_size<_Tp>::value> {};
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remove_cv looks redundant here, deduction already stripped the cv qualifiers.


https://reviews.llvm.org/D28222