/// <X_T, Y_T, JAC_T> should be <complex64, complex64, float>
/// Note that JAC_T is always real-valued, and should be an appropriate
/// precision to host the partial derivatives for dy/dx
///
/// if y = ComplexAbs(x) where x is DT_COMPLEX64 (so y is DT_FLOAT)
/// <X_T, Y_T, JAC_T> should be <complex64, float, float>
///
/// if y = Complex(x, x) where x is DT_FLOAT (so y is DT_COMPLEX64)