pub unsafe extern "C" fn weld_value_run(value: weld_value_t) -> i64 {
    let value = value as *mut weld::WeldValue;
    let value = &*value;
    value.run_id().unwrap_or(-1)
}
Returns the Run ID of the value.

If this value was not returned by a Weld program, this function returns `-1`.
weld-capi/src/lib.rs