dungeon/libs/kaguya-1.3.2/include/kaguya/metatable.hpp

// Copyright satoren
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)

#pragma once

#include <string>
#include <vector>
#include <map>
#include <typeinfo>

#include "kaguya/config.hpp"
#include "kaguya/push_any.hpp"
#include "kaguya/native_function.hpp"
#include "kaguya/lua_ref_function.hpp"

#define KAGUYA_PROPERTY_PREFIX "_prop_"

namespace kaguya {

#define KAGUYA_PP_STRUCT_TDEF_REP(N) KAGUYA_PP_CAT(class A, N) = void
#define KAGUYA_PP_STRUCT_TEMPLATE_DEF_REPEAT(N)                                \
  KAGUYA_PP_REPEAT_ARG(N, KAGUYA_PP_STRUCT_TDEF_REP)

template <KAGUYA_PP_STRUCT_TEMPLATE_DEF_REPEAT(KAGUYA_CLASS_MAX_BASE_CLASSES)>
struct MultipleBase {};
#undef KAGUYA_PP_STRUCT_TDEF_REP
#undef KAGUYA_PP_STRUCT_TEMPLATE_DEF_REPEAT
}

namespace kaguya {
struct LuaCodeChunk {
  LuaCodeChunk(const std::string &src, const std::string &name = "")
      : code_(src), chunk_name_(name) {}
  LuaCodeChunk(const char *src, const char *name = "")
      : code_(src), chunk_name_(name ? name : "") {}
  std::string code_;
  std::string chunk_name_;
};

/// @ingroup lua_type_traits
/// @brief lua_type_traits for LuaCodeChunk
template <> struct lua_type_traits<LuaCodeChunk> {
  static int push(lua_State *state, const LuaCodeChunk &ref) {
    int status = luaL_loadbuffer(
        state, ref.code_.c_str(), ref.code_.size(),
        ref.chunk_name_.empty() ? ref.code_.c_str() : ref.chunk_name_.c_str());
    if (!except::checkErrorAndThrow(status, state)) {
      return 0;
    }
    return 1;
  }
};
struct LuaCodeChunkExecute : LuaCodeChunk {
  LuaCodeChunkExecute(const std::string &src, const std::string &name = "")
      : LuaCodeChunk(src, name) {}
  LuaCodeChunkExecute(const char *src, const char *name = "")
      : LuaCodeChunk(src, name) {}
};
typedef LuaCodeChunkExecute LuaCodeChunkResult;
/// @ingroup lua_type_traits
/// @brief lua_type_traits for LuaCodeChunkResult
template <> struct lua_type_traits<LuaCodeChunkExecute> {
  static int push(lua_State *state, const LuaCodeChunkExecute &ref) {
    int status = luaL_loadbuffer(
        state, ref.code_.c_str(), ref.code_.size(),
        ref.chunk_name_.empty() ? ref.code_.c_str() : ref.chunk_name_.c_str());
    if (!except::checkErrorAndThrow(status, state)) {
      return 0;
    }
    status = lua_pcall_wrap(state, 0, 1);
    if (!except::checkErrorAndThrow(status, state)) {
      return 0;
    }
    return 1;
  }
};

namespace Metatable {
typedef std::map<std::string, AnyDataPusher> PropMapType;
typedef std::map<std::string, AnyDataPusher> MemberMapType;

inline bool is_property_key(const char *keyname) {
  return keyname &&
         strncmp(keyname, KAGUYA_PROPERTY_PREFIX,
                 sizeof(KAGUYA_PROPERTY_PREFIX) - 1) != 0;
}
inline int property_index_function(lua_State *L) {
  // Lua
  // local arg = {...};local metatable = arg[1];
  // return function(table, index)
  // if string.find(index,KAGUYA_PROPERTY_PREFIX)~=0 then
  // local propfun = metatable[KAGUYA_PROPERTY_PREFIX ..index];
  // if propfun then return propfun(table) end
  // end
  // return metatable[index]
  // end
  static const int table = 1;
  static const int key = 2;
  static const int metatable = lua_upvalueindex(1);
  const char *strkey = lua_tostring(L, key);

  if (lua_type(L, 1) == LUA_TUSERDATA && is_property_key(strkey)) {
    int type = lua_getfield_rtype(
        L, metatable, (KAGUYA_PROPERTY_PREFIX + std::string(strkey)).c_str());
    if (type == LUA_TFUNCTION) {
      lua_pushvalue(L, table);
      lua_call(L, 1, 1);
      return 1;
    }
  }
  lua_pushvalue(L, key);
  lua_gettable(L, metatable);
  return 1;
}
inline int property_newindex_function(lua_State *L) {
  // Lua
  // local arg = {...};local metatable = arg[1];
  // return function(table, index, value)
  // if type(table) == 'userdata' then
  // if string.find(index,KAGUYA_PROPERTY_PREFIX)~=0 then
  // local propfun = metatable[KAGUYA_PROPERTY_PREFIX..index];
  // if propfun then return propfun(table,value) end
  // end
  // end
  // rawset(table,index,value)
  // end
  static const int table = 1;
  static const int key = 2;
  static const int value = 3;
  static const int metatable = lua_upvalueindex(1);
  const char *strkey = lua_tostring(L, 2);

  if (lua_type(L, 1) == LUA_TUSERDATA && is_property_key(strkey)) {
    int type = lua_getfield_rtype(
        L, metatable, (KAGUYA_PROPERTY_PREFIX + std::string(strkey)).c_str());
    if (type == LUA_TFUNCTION) {
      lua_pushvalue(L, table);
      lua_pushvalue(L, value);
      lua_call(L, 2, 0);
      return 0;
    }
  }
  lua_pushvalue(L, key);
  lua_pushvalue(L, value);
  lua_rawset(L, table);
  return 0;
}

inline int multiple_base_index_function(lua_State *L) {
  // Lua
  // local arg = {...};local metabases = arg[1];
  // return function(t, k)
  // for i = 1,#metabases do
  // local v = metabases[i][k]
  // if v then
  // t[k] = v
  // return v end
  // end
  // end
  static const int table = 1;
  static const int key = 2;
  static const int metabases = lua_upvalueindex(1);

  lua_pushnil(L);
  while (lua_next(L, metabases) != 0) {
    if (lua_type(L, -1) == LUA_TTABLE) {
      lua_pushvalue(L, key);
      int type = lua_gettable_rtype(L, -2);
      if (type != LUA_TNIL) {
        lua_pushvalue(L, key);
        lua_pushvalue(L, -2);
        lua_settable(L, table);
        return 1;
      }
    }
    lua_settop(L, 3); // pop value
  }
  return 0;
}

inline int call_constructor_function(lua_State *L) {
  // function(t,...) return t.new(...) end
  lua_getfield(L, 1, "new");
  lua_replace(L, 1);
  lua_call(L, lua_gettop(L) - 1, LUA_MULTRET);
  return lua_gettop(L);
}
inline void get_call_constructor_metatable(lua_State *L) {
  static int key = 0;

  int ttype = lua_rawgetp_rtype(L, LUA_REGISTRYINDEX, &key);
  if (ttype != LUA_TTABLE) {
    lua_pop(L, 1);
    lua_createtable(L, 0, 1);
    lua_pushstring(L, "__call");
    lua_pushcfunction(L, &call_constructor_function);
    lua_rawset(L, -3);
    lua_pushvalue(L, -1);
    lua_rawsetp(L, LUA_REGISTRYINDEX, &key);
  }
}

inline void setMembers(lua_State *state, int metatable_index,
                       const MemberMapType &member_map,
                       const PropMapType &property_map) {
  for (MemberMapType::const_iterator it = member_map.begin();
       it != member_map.end(); ++it) {
    util::one_push(state, it->first);
    util::one_push(state, it->second);
    lua_rawset(state, metatable_index);
  }
  for (PropMapType::const_iterator it = property_map.begin();
       it != property_map.end(); ++it) {
    util::one_push(state, KAGUYA_PROPERTY_PREFIX + it->first);
    util::one_push(state, it->second);
    lua_rawset(state, metatable_index);
  }
}

inline void setPropertyIndexMetamethod(lua_State *state, int metatable_index) {
  lua_pushstring(state, "__index");
  lua_pushvalue(state, metatable_index);
  lua_pushcclosure(state, &property_index_function, 1);
  lua_rawset(state, metatable_index);
}

inline void setPropertyNewIndexMetamethod(lua_State *state,
                                          int metatable_index) {
  lua_pushstring(state, "__newindex");
  lua_pushvalue(state, metatable_index);
  lua_pushcclosure(state, &property_newindex_function, 1);
  lua_rawset(state, metatable_index);
}
inline void setMultipleBase(lua_State *state, int metatable_index,
                            int metabase_array_index) {
  lua_createtable(state, 0, 1);
  int newmetaindex = lua_gettop(state);
  lua_pushstring(state, "__index");
  lua_pushvalue(state, metabase_array_index); // bind metabase_array to
                                              // multiple_base_index_function
  lua_pushcclosure(state, &multiple_base_index_function, 1);
  lua_rawset(state,
             newmetaindex); // newmeta["__index"] = multiple_base_index_function
  lua_setmetatable(state, metatable_index); // metatable.setMetatable(newmeta);
}
}

/// class binding interface.
template <typename class_type, typename base_class_type = void>
class UserdataMetatable {
public:
  UserdataMetatable() {
    addStaticFunction("__gc", &class_userdata::destructor<ObjectWrapperBase>);

    KAGUYA_STATIC_ASSERT(is_registerable<class_type>::value ||
                             !traits::is_std_vector<class_type>::value,
                         "std::vector is binding to lua-table by default.If "
                         "you wants register for std::vector yourself,"
                         "please define KAGUYA_NO_STD_VECTOR_TO_TABLE");

    KAGUYA_STATIC_ASSERT(is_registerable<class_type>::value ||
                             !traits::is_std_map<class_type>::value,
                         "std::map is binding to lua-table by default.If you "
                         "wants register for std::map yourself,"
                         "please define KAGUYA_NO_STD_MAP_TO_TABLE");

    // can not register push specialized class
    KAGUYA_STATIC_ASSERT(is_registerable<class_type>::value,
                         "Can not register specialized of type conversion "
                         "class. e.g. std::tuple");
  }

  LuaTable createMatatable(lua_State *state) const {
    util::ScopedSavedStack save(state);
    if (!class_userdata::newmetatable<class_type>(state)) {
      except::OtherError(state, typeid(class_type *).name() +
                                    std::string(" is already registered"));
      return LuaTable();
    }
    int metatable_index = lua_gettop(state);
    Metatable::setMembers(state, metatable_index, member_map_, property_map_);

    if (!traits::is_same<base_class_type, void>::value ||
        !property_map_.empty()) // if base class has property and derived class
                                // hasnt property. need property access
                                // metamethod
    {
      if (member_map_.count("__index") == 0) {
        Metatable::setPropertyIndexMetamethod(state, metatable_index);
      }

      if (member_map_.count("__newindex") == 0) {
        Metatable::setPropertyNewIndexMetamethod(state, metatable_index);
      }
    } else {
      if (member_map_.count("__index") == 0) {
        lua_pushstring(state, "__index");
        lua_pushvalue(state, metatable_index);
        lua_rawset(state, metatable_index);
      }
    }

    set_base_metatable(state, metatable_index,
                       types::typetag<base_class_type>());

    if (lua_getmetatable(state, metatable_index)) // get base_metatable
    {
      lua_pushstring(state, "__call");
      lua_pushcfunction(state, &Metatable::call_constructor_function);
      lua_rawset(state, -3); // base_metatable["__call"] =
                             // Metatable::call_constructor_function
    } else {
      Metatable::get_call_constructor_metatable(state);
      lua_setmetatable(state, metatable_index);
    }

    return LuaStackRef(state, metatable_index);
  }

#if KAGUYA_USE_CPP11
  template <typename... ArgTypes> UserdataMetatable &setConstructors() {
    addOverloadedFunctions(
        "new", typename ConstructorFunction<class_type, ArgTypes>::type()...);
    return *this;
  }
#else
#define KAGUYA_SET_CON_TYPE_DEF(N)                                             \
  typename ConstructorFunction<class_type, KAGUYA_PP_CAT(A, N)>::type()
#define KAGUYA_SET_CON_FN_DEF(N)                                               \
  template <KAGUYA_PP_TEMPLATE_DEF_REPEAT(N)>                                  \
  inline UserdataMetatable &setConstructors() {                                \
    addOverloadedFunctions("new",                                              \
                           KAGUYA_PP_REPEAT_ARG(N, KAGUYA_SET_CON_TYPE_DEF));  \
    return *this;                                                              \
  }

  KAGUYA_PP_REPEAT_DEF(KAGUYA_FUNCTION_MAX_OVERLOADS, KAGUYA_SET_CON_FN_DEF)
#undef KAGUYA_SET_CON_FN_DEF
#undef KAGUYA_SET_CON_TYPE_DEF

#endif

  /// @brief add member property with getter function.(experimental)
  /// @param name function name for lua
  /// @param mem bind member data
  template <typename Ret>
  UserdataMetatable &addProperty(const char *name, Ret class_type::*mem) {
    if (has_key(name)) {
      throw KaguyaException(std::string(name) + " is already registered.");
      return *this;
    }
    property_map_[name] = AnyDataPusher(kaguya::function(mem));
    return *this;
  }

  /// @brief add member property with getter function.(experimental)
  /// @param name function name for lua
  /// @param getter getter function
  template <typename GetType>
  UserdataMetatable &addProperty(const char *name,
                                 GetType (class_type::*getter)() const) {
    if (has_key(name)) {
      throw KaguyaException(std::string(name) + " is already registered.");
      return *this;
    }
    property_map_[name] = AnyDataPusher(kaguya::function(getter));
    return *this;
  }

  /// @brief add member property with setter, getter functions.(experimental)
  /// @param name function name for lua
  /// @param getter getter function
  /// @param setter setter function
  template <typename GetType>
  UserdataMetatable &addProperty(const char *name,
                                 GetType (*getter)(const class_type *)) {
    if (has_key(name)) {
      throw KaguyaException(std::string(name) + " is already registered.");
      return *this;
    }
    property_map_[name] = AnyDataPusher(function(getter));
    return *this;
  }
  /// @brief add member property with setter, getter functions.(experimental)
  /// @param name function name for lua
  /// @param getter getter function
  /// @param setter setter function
  template <typename GetType>
  UserdataMetatable &addProperty(const char *name,
                                 GetType (*getter)(const class_type &)) {
    if (has_key(name)) {
      throw KaguyaException(std::string(name) + " is already registered.");
      return *this;
    }
    property_map_[name] = AnyDataPusher(function(getter));
    return *this;
  }

  /// @brief add member property with setter, getter functions.(experimental)
  /// @param name function name for lua
  /// @param getter getter function
  /// @param setter setter function
  template <typename GetType, typename SetType>
  UserdataMetatable &addProperty(const char *name,
                                 GetType (class_type::*getter)() const,
                                 void (class_type::*setter)(SetType)) {
    if (has_key(name)) {
      throw KaguyaException(std::string(name) + " is already registered.");
      return *this;
    }
    property_map_[name] = AnyDataPusher(overload(getter, setter));
    return *this;
  }

  /// @brief add member property with external setter, getter
  /// functions.(experimental)
  /// @param name function name for lua
  /// @param getter getter function
  /// @param setter setter function
  template <typename GetType, typename SetType>
  UserdataMetatable &addProperty(const char *name,
                                 GetType (*getter)(const class_type *),
                                 void (*setter)(class_type *, SetType)) {
    if (has_key(name)) {
      throw KaguyaException(std::string(name) + " is already registered.");
      return *this;
    }
    property_map_[name] = AnyDataPusher(overload(getter, setter));
    return *this;
  }

  /// @brief add member property with external setter, getter
  /// functions.(experimental)
  /// @param name function name for lua
  /// @param getter getter function
  /// @param setter setter function
  template <typename GetType, typename SetType>
  UserdataMetatable &addProperty(const char *name,
                                 GetType (*getter)(const class_type &),
                                 void (*setter)(class_type &, SetType)) {
    if (has_key(name)) {
      throw KaguyaException(std::string(name) + " is already registered.");
      return *this;
    }
    property_map_[name] = AnyDataPusher(overload(getter, setter));
    return *this;
  }

  /// @brief add member property with getter function.(experimental)
  /// @param name function name for lua
  /// @param getter getter function
  template <typename GetterType>
  UserdataMetatable &addPropertyAny(const char *name, GetterType getter) {
    if (has_key(name)) {
      throw KaguyaException(std::string(name) + " is already registered.");
      return *this;
    }
    property_map_[name] = AnyDataPusher(function(getter));
    return *this;
  }
  /// @brief add member property with setter, getter functions.(experimental)
  /// @param name function name for lua
  /// @param getter getter function
  /// @param setter setter function
  template <typename GetterType, typename SetterType>
  UserdataMetatable &addPropertyAny(const char *name, GetterType getter,
                                    SetterType setter) {
    if (has_key(name)) {
      throw KaguyaException(std::string(name) + " is already registered.");
      return *this;
    }
    property_map_[name] = AnyDataPusher(overload(getter, setter));
    return *this;
  }

  /// @brief add non member function
  /// @param name function name for lua
  /// @param f function
  template <typename Fun>
  UserdataMetatable &addStaticFunction(const char *name, Fun f) {
    if (has_key(name)) {
      throw KaguyaException(std::string(name) + " is already registered.");
      return *this;
    }
    member_map_[name] = AnyDataPusher(kaguya::function(f));
    return *this;
  }

#if KAGUYA_USE_CPP11
  /// @brief assign overloaded from functions.
  /// @param name name for lua
  /// @param f functions
  template <typename... Funcs>
  UserdataMetatable &addOverloadedFunctions(const char *name, Funcs... f) {
    if (has_key(name)) {
      throw KaguyaException(std::string(name) + " is already registered.");
      return *this;
    }

    member_map_[name] = AnyDataPusher(overload(f...));

    return *this;
  }

  /// @brief assign data by argument value.
  /// @param name name for lua
  /// @param d data
  template <typename Data>
  UserdataMetatable &addStaticField(const char *name, Data &&d) {
    if (has_key(name)) {
      throw KaguyaException(std::string(name) + " is already registered.");
      return *this;
    }
    member_map_[name] = AnyDataPusher(std::forward<Data>(d));
    return *this;
  }
#else

#define KAGUYA_ADD_OVERLOAD_FUNCTION_DEF(N)                                    \
  template <KAGUYA_PP_TEMPLATE_DEF_REPEAT(N)>                                  \
  inline UserdataMetatable &addOverloadedFunctions(                            \
      const char *name, KAGUYA_PP_ARG_CR_DEF_REPEAT(N)) {                      \
    if (has_key(name)) {                                                       \
      throw KaguyaException(std::string(name) + " is already registered.");    \
      return *this;                                                            \
    }                                                                          \
    member_map_[name] =                                                        \
        AnyDataPusher(kaguya::overload(KAGUYA_PP_ARG_REPEAT(N)));              \
    return *this;                                                              \
  }

  KAGUYA_PP_REPEAT_DEF(KAGUYA_FUNCTION_MAX_OVERLOADS,
                       KAGUYA_ADD_OVERLOAD_FUNCTION_DEF)
#undef KAGUYA_ADD_OVERLOAD_FUNCTION_DEF

  /// @brief assign data by argument value.
  /// @param name name for lua
  /// @param d data
  template <typename Data>
  UserdataMetatable &addStaticField(const char *name, const Data &d) {
    if (has_key(name)) {
      throw KaguyaException(std::string(name) + " is already registered.");
      return *this;
    }
    member_map_[name] = AnyDataPusher(d);
    return *this;
  }
#endif

#if defined(_MSC_VER) && _MSC_VER <= 1800
  // can not write  Ret class_type::* f on MSC++2013
  template <typename Fun>
  UserdataMetatable &addFunction(const char *name, Fun f) {
    if (has_key(name)) {
      throw KaguyaException(std::string(name) + " is already registered. To "
                                                "overload a function, use "
                                                "addOverloadedFunctions");
      return *this;
    }
    member_map_[name] = AnyDataPusher(kaguya::function(f));
    return *this;
  }
#else
  /// @brief assign function
  /// @param name name for lua
  /// @param f pointer to member function.
  template <typename Ret>
  UserdataMetatable &addFunction(const char *name, Ret class_type::*f) {
    if (has_key(name)) {
      throw KaguyaException(std::string(name) + " is already registered. To "
                                                "overload a function, use "
                                                "addOverloadedFunctions");
      return *this;
    }
    member_map_[name] = AnyDataPusher(kaguya::function(f));
    return *this;
  }
#endif
  /// @brief assign function
  /// @param name name for lua
  /// @param f member function object.
  UserdataMetatable &addFunction(const char *name, PolymorphicMemberInvoker f) {
    if (has_key(name)) {
      throw KaguyaException(std::string(name) + " is already registered. To "
                                                "overload a function, use "
                                                "addOverloadedFunctions");
      return *this;
    }
    member_map_[name] = AnyDataPusher(kaguya::function(f));
    return *this;
  }

private:
  void set_base_metatable(lua_State *, int, types::typetag<void>) const {}
  template <class Base>
  void set_base_metatable(lua_State *state, int metatable_index,
                          types::typetag<Base>) const {
    class_userdata::get_metatable<Base>(state);
    lua_setmetatable(state,
                     metatable_index); // metatable.setMetatable(newmeta);
    PointerConverter &pconverter = PointerConverter::get(state);
    pconverter.add_type_conversion<Base, class_type>();
  }

#if KAGUYA_USE_CPP11

  template <typename Base>
  void metatables(lua_State *state, int metabase_array_index,
                  PointerConverter &pvtreg,
                  types::typetag<MultipleBase<Base> >) const {
    class_userdata::get_metatable<Base>(state);
    lua_rawseti(state, metabase_array_index,
                lua_rawlen(state, metabase_array_index) + 1);
    pvtreg.add_type_conversion<Base, class_type>();
  }
  template <typename Base, typename... Remain>
  void metatables(lua_State *state, int metabase_array_index,
                  PointerConverter &pvtreg,
                  types::typetag<MultipleBase<Base, Remain...> >) const {
    class_userdata::get_metatable<Base>(state);
    lua_rawseti(state, metabase_array_index,
                lua_rawlen(state, metabase_array_index) + 1);
    pvtreg.add_type_conversion<Base, class_type>();
    metatables(state, metabase_array_index, pvtreg,
               types::typetag<MultipleBase<Remain...> >());
  }

  template <typename... Bases>
  void
  set_base_metatable(lua_State *state, int metatable_index,
                     types::typetag<MultipleBase<Bases...> > metatypes) const {
    PointerConverter &pconverter = PointerConverter::get(state);

    lua_createtable(state, sizeof...(Bases), 0);
    int metabase_array_index = lua_gettop(state);
    metatables(state, metabase_array_index, pconverter, metatypes);
    Metatable::setMultipleBase(state, metatable_index, metabase_array_index);
  }

#else
#define KAGUYA_GET_BASE_METATABLE(N)                                           \
  class_userdata::get_metatable<KAGUYA_PP_CAT(A, N)>(state);                   \
  lua_rawseti(state, metabase_array_index,                                     \
              lua_rawlen(state, metabase_array_index) + 1);                    \
  pconverter.add_type_conversion<KAGUYA_PP_CAT(A, N), class_type>();
#define KAGUYA_MULTIPLE_INHERITANCE_SETBASE_DEF(N)                             \
  template <KAGUYA_PP_TEMPLATE_DEF_REPEAT(N)>                                  \
  void set_base_metatable(                                                     \
      lua_State *state, int metatable_index,                                   \
      types::typetag<MultipleBase<KAGUYA_PP_TEMPLATE_ARG_REPEAT(N)> >) const { \
    PointerConverter &pconverter = PointerConverter::get(state);               \
    lua_createtable(state, N, 0);                                              \
    int metabase_array_index = lua_gettop(state);                              \
    KAGUYA_PP_REPEAT(N, KAGUYA_GET_BASE_METATABLE);                            \
    Metatable::setMultipleBase(state, metatable_index, metabase_array_index);  \
  }

  KAGUYA_PP_REPEAT_DEF(KAGUYA_CLASS_MAX_BASE_CLASSES,
                       KAGUYA_MULTIPLE_INHERITANCE_SETBASE_DEF)
#undef KAGUYA_MULTIPLE_INHERITANCE_SETBASE_DEF
#undef KAGUYA_GET_BASE_METATABLE
#endif

  bool has_key(const std::string &key) {
    if (member_map_.count(key) > 0) {
      return true;
    }
    if (property_map_.count(key) > 0) {
      return true;
    }
    std::string propkey = KAGUYA_PROPERTY_PREFIX + key;
    if (member_map_.count(propkey) > 0) //_prop_keyname is reserved for property
    {
      return true;
    }
    return false;
  }

  Metatable::PropMapType property_map_;
  Metatable::MemberMapType member_map_;
};

/// @ingroup lua_type_traits
/// @brief lua_type_traits for UserdataMetatable
template <typename T, typename Base>
struct lua_type_traits<UserdataMetatable<T, Base> > {
  typedef const UserdataMetatable<T, Base> &push_type;

  static int push(lua_State *l, push_type ref) {
    return ref.createMatatable(l).push(l);
  }
};
}