[libcxx-commits] [libcxx] [libc++] LWG 3821 uses_allocator_construction_args should have overload for pair-like (PR #66939)

[via libcxx-commits]

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@@ -284,7 +284,8 @@ struct _LIBCPP_TEMPLATE_VIS pair
     }
 
     template <__pair_like _PairLike>
-      requires(is_constructible_v<first_type, decltype(std::get<0>(std::declval<_PairLike&&>()))> &&
+      requires(!__is_specialization_of_subrange<remove_cvref_t<_PairLike>>::value &&
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huixie90 wrote:

Actually I found an example where without the fix, it is ambiguous between `pair`'s constructor and `subranges`' `operator Pairlike`.

https://godbolt.org/z/fefaEzz9M

https://github.com/llvm/llvm-project/pull/66939