kind of fixed it, almost

Author: vinay-deshmukh

libcxx/include/__tree

@@ -1023,14 +1023,41 @@ public:
     return __emplace_hint_unique_key_args(__p, __x.first, std::forward<_Pp>(__x)).first;
   }
 
+  template<
+  class _ValueT = _Tp,
+  __enable_if_t<__is_tree_value_type<_ValueT>::value, int> = 0
+  >
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 void
+  __sfinae_call_emplace_hint_unique(const_iterator __p, __get_node_value_type_t<_Tp>&& __value, false_type) {
+      // __emplace_hint_unique(__p, std::move(__value.first), std::move(__value.second));
+      // static_assert(false, "Can not emplace during constant evaluation if the key is `const MoveOnly` ");
+      (void)__p;
+      (void)__value;
+  }
+
+  template<
+  class _ValueT = _Tp,
+  __enable_if_t<__is_tree_value_type<_ValueT>::value, int> = 0
+  >
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 void
+  __sfinae_call_emplace_hint_unique(const_iterator __p, __get_node_value_type_t<_Tp>&& __value, true_type) {
+      __emplace_hint_unique(__p, std::move(__value.first), std::move(__value.second));
+  }
+
+
   template <class _ValueT = _Tp, __enable_if_t<__is_tree_value_type<_ValueT>::value, int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 void
   __insert_unique_from_orphaned_node(const_iterator __p, __get_node_value_type_t<_Tp>&& __value) {
     // fails here for move_alloc.pass.cpp
 
     #if _LIBCPP_STD_VER >= 26
     if (__libcpp_is_constant_evaluated()) {
-      __emplace_hint_unique(__p, std::move(__value.first), std::move(__value.second));
+      // static_assert(std::same_as_v<decltype(__value.first), double>);
+      // __emplace_hint_unique(__p, std::move(__value.first), std::move(__value.second));
+
+      __sfinae_call_emplace_hint_unique(__p, std::move(__value),
+        integral_constant<bool, is_copy_constructible<decltype(__value.first)>::value >()
+      );
     } else 
     #endif
     {