In file included from main.cpp:18:0:
game_database.h:12:25: error: conflicting declaration 'using ObjectId = int64_t'
 using ObjectId = int64_t;
                         ^
main.cpp:8:40: note: previous declaration as 'using ObjectId = long long unsigned int'
 using ObjectId = unsigned long long int;
                                        ^
In file included from main.cpp:18:0:
game_database.h:14:8: error: redefinition of 'struct GameObject'
 struct GameObject {
        ^~~~~~~~~~
main.cpp:10:8: note: previous definition of 'struct GameObject'
 struct GameObject
        ^~~~~~~~~~