template <class charT, class traits, class T>
basic_istream<charT, traits>& operator>>(basic_istream<charT, traits>&& is, T&& x);
Effects: Equivalent to:
is >> std::forward<T>(x);
return is;
Remarks: This function shall not participate in overload resolution
unless the expression is >> std::forward<T>(x) is well-formed.