Start refactoring LuaStack

luprex/cpp/core/luastack.hpp

@@ -181,6 +181,7 @@ public:
     
     friend class LuaCoreStack;
     friend class LuaOldStack;
+    friend class LuaDefStack;
     friend class LuaExtStack;
 };
 
@@ -275,6 +276,8 @@ class LuaCoreStack : public eng::nevernew {
 protected:
     lua_State *L_;
     
+    LuaCoreStack(lua_State *L) : L_(L) {}
+    
 private:
     // Push any value on the stack, by type.
     void push_any_value(LuaNewTableMarker s) const { lua_newtable(L_); }
@@ -549,8 +552,7 @@ private:
 
 public:
     template<class... SS>
-    LuaOldStack(lua_State *L, SS & ... stackslots) {
-        L_ = L;
+    LuaOldStack(lua_State *L, SS & ... stackslots) : LuaCoreStack(L) {
         count_slots<0, 0, 0>(stackslots...);
         if (lua_gettop(L) < narg_) {
             luaL_error(L, "not enough arguments to function");
@@ -624,8 +626,7 @@ private:
 
 public:
     template<class... SS>
-    LuaDefStack(lua_State *L, SS & ... stackslots) {
-        L_ = L;
+    LuaDefStack(lua_State *L, SS & ... stackslots) : LuaCoreStack(L) {
         count_slots<0, 0, 0>(stackslots...);
         if (lua_gettop(L_) != narg_) {
             luaL_error(L_, "function expects exactly %d arguments", narg_);
@@ -642,11 +643,12 @@ public:
         assign_slots(1, 1 + nret_, 1 + nret_ + narg_, stackslots...);
     }
 
-    ~LuaDefStack() {
-        if (!lua_isthrowing(L_)) {
-            lua_settop(L_, nret_);
-        };
+    int result() {
+        lua_settop(L_, nret_);
+        return nret_;
     }
+
+    ~LuaDefStack() { }
 };
 
 class LuaExtStack : public LuaCoreStack {
@@ -673,8 +675,7 @@ private:
 
 public:
     template<class... SS>
-    LuaExtStack(lua_State *L, SS & ... stackslots) {
-        L_ = L;
+    LuaExtStack(lua_State *L, SS & ... stackslots) : LuaCoreStack(L) {
         count_slots<0>(stackslots...);
         lua_checkstack(L_, nvar_ + 20);
         oldtop_ = lua_gettop(L_);
@@ -685,8 +686,7 @@ public:
     }
 
     template<class... SS>
-    LuaExtStack(const LuaCoreStack &LS0, SS & ... stackslots) {
-        L_ = LS0.state();
+    LuaExtStack(const LuaCoreStack &LS0, SS & ... stackslots) : LuaCoreStack(LS0.state()) {
         count_slots<0>(stackslots...);
         lua_checkstack(L_, nvar_ + 20);
         oldtop_ = lua_gettop(L_);