salsa/components/salsa-macro-rules/src/unexpected_cycle_recovery.rs

// Macro that generates the body of the cycle recovery function
// for the case where no cycle recovery is possible. This has to be
// a macro because it can take a variadic number of arguments.
#[macro_export]
macro_rules! unexpected_cycle_recovery {
    ($db:ident, $cycle:ident, $($other_inputs:ident),*) => {
        {
            std::mem::drop($db);
            std::mem::drop(($($other_inputs),*));
            panic!("cannot recover from cycle `{:?}`", $cycle)
        }
    }
}