Use Box<[]>.

src/ast.rs

@@ -72,7 +72,7 @@ pub struct ScriptFnDef {
     /// Not available under `no_function`.
     #[cfg(not(feature = "no_function"))]
     #[cfg(feature = "metadata")]
-    pub comments: StaticVec<Box<str>>,
+    pub comments: Option<Box<[Box<str>]>>,
 }
 
 impl fmt::Display for ScriptFnDef {
@@ -151,7 +151,10 @@ impl<'a> From<&'a ScriptFnDef> for ScriptFnMetadata<'a> {
         Self {
             #[cfg(not(feature = "no_function"))]
             #[cfg(feature = "metadata")]
-            comments: value.comments.iter().map(Box::as_ref).collect(),
+            comments: value
+                .comments
+                .as_ref()
+                .map_or_else(|| Vec::new(), |v| v.iter().map(Box::as_ref).collect()),
             access: value.access,
             name: &value.name,
             params: value.params.iter().map(|s| s.as_str()).collect(),

src/optimize.rs

@@ -1165,7 +1165,7 @@ pub fn optimize_into_ast(
                     mods: crate::engine::Imports::new(),
                     #[cfg(not(feature = "no_function"))]
                     #[cfg(feature = "metadata")]
-                    comments: StaticVec::new(),
+                    comments: None,
                 })
                 .for_each(|fn_def| {
                     lib2.set_script_fn(fn_def);

src/parse.rs

@@ -2733,7 +2733,7 @@ fn parse_stmt(
     #[cfg(not(feature = "no_function"))]
     #[cfg(feature = "metadata")]
     let comments = {
-        let mut comments = StaticVec::<Box<str>>::new();
+        let mut comments = Vec::<Box<str>>::new();
         let mut comments_pos = Position::NONE;
 
         // Handle doc-comments.
@@ -2996,7 +2996,7 @@ fn parse_fn(
     settings: ParseSettings,
     #[cfg(not(feature = "no_function"))]
     #[cfg(feature = "metadata")]
-    comments: StaticVec<Box<str>>,
+    comments: Vec<Box<str>>,
 ) -> Result<ScriptFnDef, ParseError> {
     let mut settings = settings;
 
@@ -3078,7 +3078,11 @@ fn parse_fn(
         mods: crate::engine::Imports::new(),
         #[cfg(not(feature = "no_function"))]
         #[cfg(feature = "metadata")]
-        comments,
+        comments: if comments.is_empty() {
+            None
+        } else {
+            Some(comments.into())
+        },
     })
 }
 
@@ -3223,7 +3227,7 @@ fn parse_anon_fn(
         mods: crate::engine::Imports::new(),
         #[cfg(not(feature = "no_function"))]
         #[cfg(feature = "metadata")]
-        comments: StaticVec::new(),
+        comments: None,
     };
 
     let fn_ptr = crate::FnPtr::new_unchecked(fn_name, StaticVec::new());

src/serde/metadata.rs

@@ -165,7 +165,8 @@ impl From<&crate::module::FuncInfo> for FnMetadata {
                         .get_script_fn_def()
                         .expect("scripted function")
                         .comments
-                        .to_vec()
+                        .as_ref()
+                        .map_or_else(|| Vec::new(), |v| v.to_vec())
                 }
             } else {
                 Vec::new()