[phobos] FFT

[Walter Bright]

Don Clugston wrote:
>
> Anyway, the reason I posted the link was not so much to help with
> implementation, but more because it gives a great feel for what's
> involved in a "state of the art" FFT library. I suspect there's a
> sweet spot with high convenience, small code size, and good-enough
> performance.
>
>   

The most important thing for a Phobos implementation of FFT (or any 
other module) is getting the API right. Having that right means we can 
always swap it out for a better implementation without breaking user code.