Function rust_util::util_io::copy_io_callback

pub fn copy_io_callback<R: ?Sized, W: ?Sized, FCallback>(
    reader: &mut R, 
    writer: &mut W, 
    total: i64, 
    callback: &FCallback
) -> Result<u64> where
    R: Read,
    W: Write,
    FCallback: Fn(i64, u64, usize),