drop_bomb

A runtime guard for (protecting your precious bodily fluids) implementing linear types. See the docs for more.

lib.rs:

drop_bomb

drop_bomb provides two types, DropBomb and DebugDropBomb, which panic in drop with a specified message unless defused. This is useful as a building-block for runtime-checked linear types.

For example, one can build a variant of BufWriter which enforces handling of errors during flush.

extern crate drop_bomb;

use std::io::{Write, BufWriter, Result};
use drop_bomb::DropBomb;

struct CheckedBufWriter<W: Write> {
    inner: BufWriter<W>,
    bomb: DropBomb,
}

impl<W: Write> CheckedBufWriter<W> {
    fn new(inner: BufWriter<W>) -> CheckedBufWriter<W> {
        let bomb = DropBomb::new(
            "CheckedBufWriter must be explicitly closed \
             to handle potential errors on flush"
        );
        CheckedBufWriter { inner, bomb }
    }

    fn close(mut self) -> Result<()> {
        self.bomb.defuse();
        self.inner.flush()?;
        Ok(())
    }
}

Notes:

• Bombs do nothing if a thread is already panicking.
• When #[cfg(debug_assertions)] is disabled, DebugDropBomb is always defused and has a zero size.