constfft

A Rust library crate providing an [FFT] API for arrays. This crate wraps the [rustfft] and [realfft] crates that does the heavy lifting behind the scenes. Use constfft if you're working with [arrays], i.e. you know the size of the signal at compile time.

Advantages

• If it compiles, your code won't panic™ in this library[^panic]
• Ergonomic API

Current limitations

• Requires nightly because it uses the [genericconstexprs] feature
• No caching of the intermediate context/structs required to do the fft calculation
• Even/Odd bounds don't seem to propagate back up the call chain (TODO: Add example and link to rust issue)
• No implementation for slices

Possible future plans

Currently I don't see any reason why the same API (minus the compile time size checks) cannot be implementable on slices. This seems like a much nicer API to work with and AFAICT does not depend on the types to be arrays. If this is the case I'd implement the same API on slices and rename this crate to easyfft.

Footnotes

Currently you can create a RealDft struct and mutate it using the DerefMut trait in a way that the real_ifft method will cause a panic. This should be fixable in a future patch release currently pending implementation details. There could be other bugs in this crate or it's dependencies that may cause a panic, but in theory all the runtime panics have been moved to compile time errors.