1 files changed, 23 insertions, 0 deletions
diff --git a/compiler/rustc_builtin_macros/src/deriving/bounds.rs b/compiler/rustc_builtin_macros/src/deriving/bounds.rs
index 0481a118906..2c8e6f99c67 100644
--- a/compiler/rustc_builtin_macros/src/deriving/bounds.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/bounds.rs
@@ -27,3 +27,26 @@ pub fn expand_deriving_copy(
 
     trait_def.expand(cx, mitem, item, push);
 }
+
+pub fn expand_deriving_const_param_ty(
+    cx: &mut ExtCtxt<'_>,
+    span: Span,
+    mitem: &MetaItem,
+    item: &Annotatable,
+    push: &mut dyn FnMut(Annotatable),
+    is_const: bool,
+) {
+    let trait_def = TraitDef {
+        span,
+        path: path_std!(marker::ConstParamTy),
+        skip_path_as_bound: false,
+        needs_copy_as_bound_if_packed: false,
+        additional_bounds: Vec::new(),
+        supports_unions: false,
+        methods: Vec::new(),
+        associated_types: Vec::new(),
+        is_const,
+    };
+
+    trait_def.expand(cx, mitem, item, push);
+}