No optimized inverse FFT implementation for real time-domain data

[seeker-Liu]

In the C++ implementation, we now have optimized FFT implementation for real input. However the ifft counterpart of the optimized implementation cannot be found. Given that the implementation I mentioned can be found in the C part (namely, the kiss_fftri() function), can I consider it a TODO for this library?

[seeker-Liu]

If my suggestion is considered favorable, I may implement it a few days later.

[mborgerding]

That sounds great. Can you please add corresponding tests, too?

[seeker-Liu]

That sounds great. Can you please add corresponding tests, too?

I'll try, but I am afraid of I am not experienced enough.

[seeker-Liu]

@mborgerding If I get it right, this library is supposed to be able to work on C++98?

[mborgerding]

If it is easy. c++98 compatibility would be nice.