warning: unsafe function's docs miss `# Safety` section
   --> src/write.rs:123:5
    |
123 |     pub unsafe fn into_box(mut self) -> Box<T> {
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#missing_safety_doc
    = note: `#[warn(clippy::missing_safety_doc)]` on by default