Use locked_read.

src/func/call.rs

@@ -1222,7 +1222,7 @@ impl Engine {
                 let (mut target, _pos) =
                     self.search_namespace(scope, global, lib, this_ptr, first_expr, level)?;
 
-                if target.as_ref().is_read_only() {
+                if target.is_read_only() {
                     target = target.into_owned();
                 }
 

src/func/mod.rs

@@ -22,8 +22,8 @@ pub use hashing::{
     combine_hashes, get_hasher,
 };
 pub use native::{
-    locked_read, locked_write, shared_make_mut, shared_take, shared_take_or_clone, shared_try_take,
-    FnAny, FnPlugin, IteratorFn, Locked, NativeCallContext, SendSync, Shared,
+    locked_read, locked_write, shared_get_mut, shared_make_mut, shared_take, shared_take_or_clone,
+    shared_try_take, FnAny, FnPlugin, IteratorFn, Locked, NativeCallContext, SendSync, Shared,
 };
 pub use plugin::PluginFunction;
 pub use register::RegisterNativeFunction;