any& operator=(const any& rhs);
any& operator=(any&& rhs) noexcept;
Postconditions: The state of *this is equivalent to the original state of rhs and rhs is left in a valid but otherwise unspecified state.
any& operator=(T&& rhs);
Effects: Constructs an object tmp of type any that contains an object of type VT direct-initialized with std::forward<T>(rhs), and tmp.swap(*this). No effects if an exception is thrown.
Remarks: This operator shall not participate in overload resolution unless VT is not the same type as any and is_copy_constructible_v<VT> is true.