add UnwindSafe

vm/src/lib.rs

@@ -24,15 +24,16 @@ use pest_meta::ast::RuleType;
 use pest_meta::optimizer::{OptimizedExpr, OptimizedRule};
 
 use std::collections::HashMap;
-use std::panic::RefUnwindSafe;
+use std::panic::{RefUnwindSafe, UnwindSafe};
 
 mod macros;
 
 /// A callback function that is called when a rule is matched.
 /// The first argument is the name of the rule and the second is the span of the rule.
 /// The function should return `true` if parsing should be terminated
 /// (if the new parsing session was started) or `false` otherwise.
-type ListenerFn = Box<dyn Fn(String, &Position<'_>) -> bool + Sync + Send + RefUnwindSafe>;
+type ListenerFn =
+    Box<dyn Fn(String, &Position<'_>) -> bool + Sync + Send + RefUnwindSafe + UnwindSafe>;
 
 /// A virtual machine-like construct that runs an AST on-the-fly
 pub struct Vm {