Proposed resolution:

This wording is relative to N4606.

1. Modify [any.nonmembers] as indicated:

   template<class ValueType>
     ValueType any_cast(const any& operand);
   template<class ValueType>
     ValueType any_cast(any& operand);
   template<class ValueType>
     ValueType any_cast(any&& operand);
   

   -?- Let U be the type remove_cv_t<remove_reference_t<ValueType>>.

   -4- Requires: is_reference_v<ValueType> is true or is_copy_constructible_v<ValueType> is true.For the first overload, is_constructible_v<ValueType, const U&> is true. For the second overload, is_constructible_v<ValueType, U&> is true. For the third overload, is_constructible_v<ValueType, U> is true. Otherwise the program is ill-formed.

   -5- Returns: For the first form, *any_cast<add_const_t<remove_reference_t<ValueType>>>(&operand). For the second and third forms, *any_cast<remove_reference_t<ValueType>>(&operand).For the first and second overload, static_cast<ValueType>(*any_cast<U>(&operand)). For the third overload, static_cast<ValueType>(std::move(*any_cast<U>(&operand))).

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