Function sharpen::classify_::classify_as_vec

pub fn classify_as_vec<'a, Input, FnT, TT: 'a, TC>(
    input: Input, 
    fnx: FnT
) -> Vec<(TC, Vec<TT>)> where
    Input: IntoIterator<Item = TT>,
    FnT: FnMut(&TT) -> TC,
    TC: Copy + Default + PartialEq,