pub unsafe extern "C" fn fftwf_plan_guru64_split_dft( rank: c_int, dims: *const fftwf_iodim64, howmany_rank: c_int, howmany_dims: *const fftwf_iodim64, ri: *mut f32, ii: *mut f32, ro: *mut f32, io: *mut f32, flags: c_uint) -> fftwf_plan