[std.numeric.fft] Arbitrary sized FFT

[bachmeier]

On Saturday, 5 November 2022 at 14:47:40 UTC, RIG_ wrote:
> I have thought about using [`fftw`](https://www.fftw.org/), but 
> it feels like doing `fft`s should in the standard library.

I don't think so. D is a general purpose programming language. 
Note that you are talking about Python as an option, but you're 
actually referring to numpy, which is a Python library the user 
has to install.

One of the selling points of D is its interoperability with other 
languages. If for whatever reason you don't want to call C, you 
can [call Python to do that part of the 
analysis](https://pyd.dpldocs.info/v0.14.3/source/pyd.embedded.d.html).