pub unsafe extern "C" fn fftwf_plan_guru64_split_dft_r2c(
rank: c_int,
dims: *const fftwf_iodim64,
howmany_rank: c_int,
howmany_dims: *const fftwf_iodim64,
in_: *mut f32,
ro: *mut f32,
io: *mut f32,
flags: c_uint,
) -> fftwf_plan