Function meta_isvalid

library/LuaWrapper.cpp:1085–1116

* Metamethod: df.isvalid(obj[,allow_null]) */

 * Metamethod: df.isvalid(obj[,allow_null])
 */
static int meta_isvalid(lua_State *state)
{
    luaL_checkany(state, 1);

    switch (Lua::IsDFObject(state, 1))
    {
    case Lua::OBJ_NULL:
        lua_settop(state, 2);
        if (lua_toboolean(state, 2))
            lua_pushvalue(state, lua_upvalueindex(1));
        else
            lua_pushnil(state);
        return 1;

    case Lua::OBJ_TYPE:
        lua_pushvalue(state, lua_upvalueindex(2));
        return 1;

    case Lua::OBJ_VOIDPTR:
        lua_pushvalue(state, lua_upvalueindex(3));
        return 1;

    case Lua::OBJ_REF:
        lua_pushvalue(state, lua_upvalueindex(4));
        return 1;

    case Lua::OBJ_INVALID:
    default:
        lua_pushnil(state);
        return 1;
    }
}

/**
 * Metamethod: df.isnull(obj)