Function template pow shall have additional overloads sufficient to
ensure, for a call with at least one argument of type complex<T>:

- 1.If either argument has type complex<long double> or type long double, then both arguments are effectively cast to complex<long double>.
- 2.Otherwise, if either argument has type complex<double>, double, or an integer type, then both arguments are effectively cast to complex<double>.
- 3.Otherwise, if either argument has type complex<float> or float, then both arguments are effectively cast to complex<float>.