Since SliceExt::split conflicts with BufRead::split, you have to use SliceExt::split(var, cond). But this doesn't give you auto-deref and if var == &&[u8] you get the confusing message that SliceExt is not implemented for &[u8] and you have to first notice that var is &&[u8] and then remember that SliceExt is implemented on [u8] and not &[u8].
Since SliceExt::split conflicts with BufRead::split, you have to use SliceExt::split(var, cond). But this doesn't give you auto-deref and if var == &&[u8] you get the confusing message that SliceExt is not implemented for &[u8] and you have to first notice that var is &&[u8] and then remember that SliceExt is implemented on [u8] and not &[u8].