index_factory at index/mod.rs in faiss-rs

index_factory.rs

/// Use the index factory to create a native instance of a Faiss index, for `d`-dimensional
/// vectors.
pub fn index_factory<D: AsRef<str>>(
    d: u32,
    description: D,
    metric: MetricType,
) -> Result<IndexImpl> {
    unsafe {
        let metric = metric as c_uint;
        let description = CString::new(description.as_ref()).map_err(|_| Error::IndexDescription)?;
        let mut index_ptr = ::std::ptr::null_mut();
        faiss_try!(faiss_index_factory(
            &mut index_ptr,
            (d & 0x7FFFFFFF) as i32,
            description.as_ptr(),
            metric
        ));
        Ok(IndexImpl { inner: index_ptr })
    }
}