static_cast complex

I would like to use static_cast to convert complex to complex.

Convert complex<int16_t> to complex<double>

I am trying to do the same thing as in this post, but I need to use static_cast. The reason I cannot use that solution is because I am using Eigen which uses static_cast in its cast() function. Is there a way to extend the functionality of static_cast to convert in this way? Or is there a way to extend Eigen's cast() function to handle this conversion?

This is basically what I am attempting:

Eigen::Array<std::complex<short>, Eigen::Dynamic, 1> short_array;
Eigen::Array<std::complex<double>, Eigen::Dynamic, 1> double_array;
double_array = short_array.cast< std::complex<double> >();