Macro continue_if 

macro_rules! continue_if {
    ($cond:expr $(,)?) => { ... };
    ($cond:expr, $($arg:tt)+) => { ... };
}

Available on crate feature sim only.

Continues the current simulation instance only if the given condition holds, otherwise stopping and discarding the instance.

This is the same concept as assume in verification tools and property-based testing libraries (e.g. kani::assume or proptest’s prop_assume!). It is useful inside simulation tests (crate::sim::flow::SimFlow::fuzz, crate::sim::flow::SimFlow::exhaustive, and the corresponding crate::sim::compiled::CompiledSim APIs) to restrict exploration to executions that satisfy some precondition. When the condition is false, the current instance is stopped and discarded: it is not treated as a test failure (and will never be recorded as a fuzzing reproducer), and the fuzzer / exhaustive search simply moves on to the next instance. If logging is enabled (always during replays, or when HYDRO_SIM_LOG=1), the failed assumption is logged.

Like the standard assert! macro, an optional custom message with format arguments can be provided.

flow.sim().fuzz(async || {
    in_send.send_many([1, 2]);
    let all: Vec<u32> = out_recv.collect().await;
    hydro_lang::sim::continue_if!(all.len() == 2, "expected both values in one batch, got {:?}", all);
    // ... assertions that only make sense when the assumption holds ...
});