User lmiq articulates the sentiment well in a later comment in the OP thread:
> what I find more interesting here is that the reasoning and code type applies to any composite type of a similar structure, thus we can use that to optimize other code completely unrelated to calculations with complex numbers.
It matters less whether super-optimized code can be written in Julia for this particular case (though there's some value in that too), the more important and telling part to me is that the language has features and tools that can easily be adopted to a general class of problems like this.
> what I find more interesting here is that the reasoning and code type applies to any composite type of a similar structure, thus we can use that to optimize other code completely unrelated to calculations with complex numbers.
It matters less whether super-optimized code can be written in Julia for this particular case (though there's some value in that too), the more important and telling part to me is that the language has features and tools that can easily be adopted to a general class of problems like this.