always-assert

Recoverable assertions, inspired by the use of assert() in SQLite.

```rust use always_assert::never;

fn applytransaction(&mut self, tx: Transaction) -> Result<(), TransactionAborted> { let delta = self.computedelta(&tx);

if never!(!self.check_internal_invariant(&delta)) {
    // Ok, something in this transaction messed up our internal state.
    // This really shouldn't be happening, and this signifies a bug.
    // Luckily, we can recover by just rejecting the transaction.
    return abort_transaction(tx);
}
self.commit(delta);
Ok(())

} ```