Omit argument names from function pointers that do not have argument names

1 files changed, 17 insertions, 5 deletions

diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index 7853e311a04..0d4ff6e7aa5 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -1104,17 +1104,29 @@ fn clean_args_from_types_and_names<'tcx>(
     types: &[hir::Ty<'tcx>],
     names: &[Ident],
 ) -> Arguments {
+    fn nonempty_name(ident: &Ident) -> Option<Symbol> {
+        if ident.name == kw::Underscore || ident.name == kw::Empty {
+            None
+        } else {
+            Some(ident.name)
+        }
+    }
+
+    // If at least one argument has a name, use `_` as the name of unnamed
+    // arguments. Otherwise omit argument names.
+    let default_name = if names.iter().any(|ident| nonempty_name(ident).is_some()) {
+        kw::Underscore
+    } else {
+        kw::Empty
+    };
+
     Arguments {
         values: types
             .iter()
             .enumerate()
             .map(|(i, ty)| Argument {
                 type_: clean_ty(ty, cx),
-                name: names
-                    .get(i)
-                    .map(|ident| ident.name)
-                    .filter(|ident| !ident.is_empty())
-                    .unwrap_or(kw::Underscore),
+                name: names.get(i).and_then(nonempty_name).unwrap_or(default_name),
                 is_const: false,
             })
             .collect(),