Simple bit manipulation question

New to Julia
7 
function bools_to_bytes(vec::Vector{Bool})
    vec = extend_bools(vec)
    n = length(vec)
    n == 0 && return [zero(UInt8)]
    @assert rem(n, 8) == 0
    nbytes = div(n, 8)
    return bools_to_nbytes(vec, nbytes)
end

function bools_to_nbytes(vec::Vector{Bool}, nbytes::Int)
    result = zeros(UInt8, nbytes) # preallocate result space
    for byteidx in 1:nbytes
       vecstart = 8*(byteidx-1) + 1
       boolbits = UInt8.(vec[vecstart:(vecstart+7)])
       for i in 1:8
           boolbits[i] = boolbits[i] << (8-i)
       end
       newbyte = reduce(|, boolbits)
       push!(result, newbyte)
    end
    return result[length(result)-nbytes+1:end]
end

function extend_bools(bools::Vector{Bool})
    n = length(bools)
    rm = rem(n, 8)
    while 0 < rm < 8
       push!(bools, false)
       rm += 1
    end
    return bools
end

hope this helps