Function batch_distance 

pub fn batch_distance(
    src1: &impl ToInputArray,
    src2: &impl ToInputArray,
    dist: &mut impl ToOutputArray,
    dtype: i32,
    nidx: &mut impl ToOutputArray,
    norm_type: i32,
    k: i32,
    mask: &impl ToInputArray,
    update: i32,
    crosscheck: bool,
) -> Result<()>

naive nearest neighbor finder

see http://en.wikipedia.org/wiki/Nearest_neighbor_search @todo document

C++ default parameters

• norm_type: NORM_L2
• k: 0
• mask: noArray()
• update: 0
• crosscheck: false