converting ~[u8] to u32

bits.rs

fn main() {
    let bytes : ~[u8] = ~[1,1,1]; // for example
    let len = vec::len(bytes)-1;
    let mut out: u32 = 0;
    do vec::iteri(bytes) |i, b| {
        out += (b as u32) << (8*(len-i))
    }
    io::println(u32::str(out));
}