1 files changed, 1 insertions, 0 deletions

diff --git a/src/deep.h b/src/deep.h
index bb86c20..c4c6fd7 100644
--- a/src/deep.h
+++ b/src/deep.h
@@ -66,6 +66,7 @@ class DeepFactory
     public:
     // NVI: public interface
     static void DeleteDeepObject(lua_State* L_, DeepPrelude* o_);
+    [[nodiscard]] static bool IsDeepUserdata(lua_State* const L_, int const idx_);
     [[nodiscard]] static DeepFactory* LookupFactory(lua_State* L_, int index_, LookupMode mode_);
     static void PushDeepProxy(DestState L_, DeepPrelude* o_, int nuv_, LookupMode mode_, lua_State* errL_);
     void pushDeepUserdata(DestState L_, int nuv_) const;