Function match_features 

pub fn match_features(
    features_a: &[OrbFeature],
    features_b: &[OrbFeature],
    max_distance: u32,
) -> Vec<(usize, usize)>

Match feature descriptors between two sets by brute-force nearest neighbor. Match ORB features between two sets using brute-force Hamming distance.

Returns pairs (idx_a, idx_b) for the best match of each feature in a against b, provided the distance is at most max_distance.