Add addStaticIndexMetaMethod and addStaticNewIndexMetaMethod to Class

.gitignore

@@ -4,6 +4,7 @@ Makefile
 CMakeCache.txt
 CMakeFiles/
 build/
+Build/
 *.dir/
 *.sln
 *.vcxproj

Distribution/LuaBridge/LuaBridge.h

@@ -2746,6 +2746,16 @@ template <class T, auto = typeName<T>().find_first_of('.')>
     return reinterpret_cast<void*>(0x8108);
 }
 
+[[nodiscard]] inline const void* getStaticIndexFallbackKey()
+{
+    return reinterpret_cast<void*>(0x81cc);
+}
+
+[[nodiscard]] inline const void* getStaticNewIndexFallbackKey()
+{
+    return reinterpret_cast<void*>(0x8109);
+}
+
 template <class T>
 [[nodiscard]] const void* getStaticRegistryKey() noexcept
 {
@@ -6188,6 +6198,30 @@ inline std::optional<int> try_call_index_fallback(lua_State* L)
     return std::nullopt;
 }
 
+inline std::optional<int> try_call_static_index_fallback(lua_State* L)
+{
+    LUABRIDGE_ASSERT(lua_istable(L, -1)); 
+
+    lua_rawgetp_x(L, -1, getStaticIndexFallbackKey()); 
+    if (! lua_iscfunction(L, -1))
+    {
+        lua_pop(L, 1); 
+        return std::nullopt;
+    }
+
+    lua_pushvalue(L, 2); 
+    lua_call(L, 1, 1); 
+
+    if (! lua_isnoneornil(L, -1))
+    {
+        lua_remove(L, -2); 
+        return 1;
+    }
+
+    lua_pop(L, 1); 
+    return std::nullopt;
+}
+
 template <bool IsObject>
 inline std::optional<int> try_call_index_extensible(lua_State* L, const char* key)
 {
@@ -6239,6 +6273,12 @@ inline int index_metamethod(lua_State* L)
             if (auto result = try_call_index_fallback(L))
                 return *result;
         }
+        else
+        {
+
+            if (auto result = try_call_static_index_fallback(L))
+                return *result;
+        }
 
         if (lua_istable(L, 1))
         {
@@ -6354,6 +6394,24 @@ inline std::optional<int> try_call_newindex_fallback(lua_State* L)
     return 0;
 }
 
+inline std::optional<int> try_call_static_newindex_fallback(lua_State* L)
+{
+    LUABRIDGE_ASSERT(lua_istable(L, -1)); 
+
+    lua_rawgetp_x(L, -1, getStaticNewIndexFallbackKey()); 
+    if (! lua_iscfunction(L, -1))
+    {
+        lua_pop(L, 1); 
+        return std::nullopt;
+    }
+
+    lua_pushvalue(L, 2); 
+    lua_pushvalue(L, 3); 
+    lua_call(L, 2, 0); 
+
+    return 0;
+}
+
 inline std::optional<int> try_call_newindex_extensible(lua_State* L, const char* key)
 {
     LUABRIDGE_ASSERT(key != nullptr);
@@ -6525,6 +6583,9 @@ inline int newindex_metamethod(lua_State* L)
         else
         {
 
+            if (auto result = try_call_static_newindex_fallback(L))
+                return *result;
+
             if (options.test(extensibleClass))
             {
                 if (auto result = try_call_newindex_extensible(L, key))
@@ -9600,6 +9661,64 @@ class Namespace : public detail::Registrar
             return *this;
         }
 
+        template <class Function>
+        auto addStaticIndexMetaMethod(Function function)
+            -> std::enable_if_t<!std::is_pointer_v<Function>
+                && std::is_invocable_v<Function, const LuaRef&, lua_State*>, Class<T>&>
+        {
+            using FnType = decltype(function);
+
+            assertStackState(); 
+
+            lua_newuserdata_aligned<FnType>(L, std::move(function)); 
+            lua_pushcclosure_x(L, &detail::invoke_proxy_functor<FnType>, "__index", 1); 
+            lua_rawsetp_x(L, -2, detail::getStaticIndexFallbackKey());
+
+            return *this;
+        }
+
+        Class<T>& addStaticIndexMetaMethod(LuaRef (*idxf)(const LuaRef&, lua_State*))
+        {
+            using FnType = decltype(idxf);
+
+            assertStackState(); 
+
+            lua_pushlightuserdata(L, reinterpret_cast<void*>(idxf)); 
+            lua_pushcclosure_x(L, &detail::invoke_proxy_function<FnType>, "__index", 1); 
+            lua_rawsetp_x(L, -2, detail::getStaticIndexFallbackKey());
+
+            return *this;
+        }
+
+        template <class Function>
+        auto addStaticNewIndexMetaMethod(Function function)
+            -> std::enable_if_t<!std::is_pointer_v<Function>
+                && std::is_invocable_v<Function, const LuaRef&, const LuaRef&, lua_State*>, Class<T>&>
+        {
+            using FnType = decltype(function);
+
+            assertStackState(); 
+
+            lua_newuserdata_aligned<FnType>(L, std::move(function)); 
+            lua_pushcclosure_x(L, &detail::invoke_proxy_functor<FnType>, "__newindex", 1); 
+            lua_rawsetp_x(L, -2, detail::getStaticNewIndexFallbackKey());
+
+            return *this;
+        }
+
+        Class<T>& addStaticNewIndexMetaMethod(LuaRef (*idxf)(const LuaRef&, const LuaRef&, lua_State*))
+        {
+            using FnType = decltype(idxf);
+
+            assertStackState(); 
+
+            lua_pushlightuserdata(L, reinterpret_cast<void*>(idxf)); 
+            lua_pushcclosure_x(L, &detail::invoke_proxy_function<FnType>, "__newindex", 1); 
+            lua_rawsetp_x(L, -2, detail::getStaticNewIndexFallbackKey());
+
+            return *this;
+        }
+
         template <class Getter>
         Class<T>& addProperty(const char* name, Getter getter, bool) = delete;
 

Source/LuaBridge/detail/CFunctions.h

@@ -240,6 +240,30 @@ inline std::optional<int> try_call_index_fallback(lua_State* L)
     return std::nullopt;
 }
 
+inline std::optional<int> try_call_static_index_fallback(lua_State* L)
+{
+    LUABRIDGE_ASSERT(lua_istable(L, -1)); // Stack: mt
+
+    lua_rawgetp_x(L, -1, getStaticIndexFallbackKey()); // Stack: mt, ifb (may be nil)
+    if (! lua_iscfunction(L, -1))
+    {
+        lua_pop(L, 1); // Stack: mt
+        return std::nullopt;
+    }
+
+    lua_pushvalue(L, 2); // Stack: mt, ifb, arg1 (key only, no self for static)
+    lua_call(L, 1, 1); // Stack: mt, ifbresult
+
+    if (! lua_isnoneornil(L, -1))
+    {
+        lua_remove(L, -2); // Stack: ifbresult
+        return 1;
+    }
+
+    lua_pop(L, 1); // Stack: mt
+    return std::nullopt;
+}
+
 template <bool IsObject>
 inline std::optional<int> try_call_index_extensible(lua_State* L, const char* key)
 {
@@ -292,6 +316,12 @@ inline int index_metamethod(lua_State* L)
             if (auto result = try_call_index_fallback(L))
                 return *result;
         }
+        else
+        {
+            // Repeat the lookup in the static index fallback
+            if (auto result = try_call_static_index_fallback(L))
+                return *result;
+        }
 
         // Search into self or metatable
         if (lua_istable(L, 1))
@@ -424,6 +454,24 @@ inline std::optional<int> try_call_newindex_fallback(lua_State* L)
     return 0;
 }
 
+inline std::optional<int> try_call_static_newindex_fallback(lua_State* L)
+{
+    LUABRIDGE_ASSERT(lua_istable(L, -1)); // Stack: mt
+
+    lua_rawgetp_x(L, -1, getStaticNewIndexFallbackKey()); // Stack: mt, nifb (may be nil)
+    if (! lua_iscfunction(L, -1))
+    {
+        lua_pop(L, 1); // Stack: mt
+        return std::nullopt;
+    }
+
+    lua_pushvalue(L, 2); // stack: mt, nifb, arg1 (key only, no self for static)
+    lua_pushvalue(L, 3); // stack: mt, nifb, arg1, arg2 (value)
+    lua_call(L, 2, 0); // stack: mt
+
+    return 0;
+}
+
 inline std::optional<int> try_call_newindex_extensible(lua_State* L, const char* key)
 {
     LUABRIDGE_ASSERT(key != nullptr);
@@ -610,6 +658,10 @@ inline int newindex_metamethod(lua_State* L)
         }
         else
         {
+            // Try in the static new index fallback
+            if (auto result = try_call_static_newindex_fallback(L))
+                return *result;
+
             // Try in the new index extensible
             if (options.test(extensibleClass))
             {

Source/LuaBridge/detail/ClassInfo.h

@@ -165,6 +165,24 @@ template <class T, auto = typeName<T>().find_first_of('.')>
     return reinterpret_cast<void*>(0x8108);
 }
 
+//=================================================================================================
+/**
+ * The key of the static index fall back in another metatable.
+ */
+[[nodiscard]] inline const void* getStaticIndexFallbackKey()
+{
+    return reinterpret_cast<void*>(0x81cc);
+}
+
+//=================================================================================================
+/**
+ * The key of the static new index fall back in another metatable.
+ */
+[[nodiscard]] inline const void* getStaticNewIndexFallbackKey()
+{
+    return reinterpret_cast<void*>(0x8109);
+}
+
 //=================================================================================================
 /**
  * @brief Get the key for the static table in the Lua registry.

Source/LuaBridge/detail/Namespace.h

@@ -551,6 +551,76 @@ class Namespace : public detail::Registrar
             return *this;
         }
 
+        //=========================================================================================
+        /**
+         * @brief Add a static index metamethod function fallback that is triggered when no result is found in static functions, properties or any other static members.
+         *
+         * Let the user define a fallback index (__index) metamethod for the static class table.
+         */
+        template <class Function>
+        auto addStaticIndexMetaMethod(Function function)
+            -> std::enable_if_t<!std::is_pointer_v<Function>
+                && std::is_invocable_v<Function, const LuaRef&, lua_State*>, Class<T>&>
+        {
+            using FnType = decltype(function);
+
+            assertStackState(); // Stack: const table (co), class table (cl), static table (st)
+
+            lua_newuserdata_aligned<FnType>(L, std::move(function)); // Stack: co, cl, st, function userdata (ud)
+            lua_pushcclosure_x(L, &detail::invoke_proxy_functor<FnType>, "__index", 1); // Stack: co, cl, st, function
+            lua_rawsetp_x(L, -2, detail::getStaticIndexFallbackKey());
+
+            return *this;
+        }
+
+        Class<T>& addStaticIndexMetaMethod(LuaRef (*idxf)(const LuaRef&, lua_State*))
+        {
+            using FnType = decltype(idxf);
+
+            assertStackState(); // Stack: const table (co), class table (cl), static table (st)
+
+            lua_pushlightuserdata(L, reinterpret_cast<void*>(idxf)); // Stack: co, cl, st, function ptr
+            lua_pushcclosure_x(L, &detail::invoke_proxy_function<FnType>, "__index", 1); // Stack: co, cl, st, function
+            lua_rawsetp_x(L, -2, detail::getStaticIndexFallbackKey());
+
+            return *this;
+        }
+
+        //=========================================================================================
+        /**
+         * @brief Add a static new index metamethod function fallback that is triggered when no result is found in static functions, properties or any other static members.
+         *
+         * Let the user define a fallback new index (__newindex) metamethod for the static class table.
+         */
+        template <class Function>
+        auto addStaticNewIndexMetaMethod(Function function)
+            -> std::enable_if_t<!std::is_pointer_v<Function>
+                && std::is_invocable_v<Function, const LuaRef&, const LuaRef&, lua_State*>, Class<T>&>
+        {
+            using FnType = decltype(function);
+
+            assertStackState(); // Stack: const table (co), class table (cl), static table (st)
+
+            lua_newuserdata_aligned<FnType>(L, std::move(function)); // Stack: co, cl, st, function userdata (ud)
+            lua_pushcclosure_x(L, &detail::invoke_proxy_functor<FnType>, "__newindex", 1); // Stack: co, cl, st, function
+            lua_rawsetp_x(L, -2, detail::getStaticNewIndexFallbackKey());
+
+            return *this;
+        }
+
+        Class<T>& addStaticNewIndexMetaMethod(LuaRef (*idxf)(const LuaRef&, const LuaRef&, lua_State*))
+        {
+            using FnType = decltype(idxf);
+
+            assertStackState(); // Stack: const table (co), class table (cl), static table (st)
+
+            lua_pushlightuserdata(L, reinterpret_cast<void*>(idxf)); // Stack: co, cl, st, function ptr
+            lua_pushcclosure_x(L, &detail::invoke_proxy_function<FnType>, "__newindex", 1); // Stack: co, cl, st, function
+            lua_rawsetp_x(L, -2, detail::getStaticNewIndexFallbackKey());
+
+            return *this;
+        }
+
         //=========================================================================================
         /**
          * @brief Add or replace a property member, by constructible by std::function.