In file included from main.cpp:18:0:
game_database.h:26:9: error: 'PageAllocator' does not name a type; did you mean 'FixedAllocator'?
   const PageAllocator& InnerAllocator() const noexcept { return p_a_; }
         ^~~~~~~~~~~~~
         FixedAllocator
game_database.h:29:3: error: 'PageAllocator' does not name a type; did you mean 'FixedAllocator'?
   PageAllocator p_a_;
   ^~~~~~~~~~~~~
   FixedAllocator
game_database.h: In constructor 'FixedAllocator<Tp>::FixedAllocator(uint64_t)':
game_database.h:10:9: error: class 'FixedAllocator<Tp>' does not have any field named 'p_a_'
       : p_a_(page_size), page_s_(page_size) {}
         ^~~~
game_database.h: In member function 'Tp* FixedAllocator<Tp>::Allocate()':
game_database.h:14:31: error: 'p_a_' was not declared in this scope
       temp = static_cast<Tp*>(p_a_.Allocate());
                               ^~~~
main.cpp: In function 'int main()':
main.cpp:30:5: error: 'GameDatabase' was not declared in this scope
     GameDatabase db;
     ^~~~~~~~~~~~
main.cpp:41:13: error: 'db' was not declared in this scope
             db.Remove(id);
             ^~
main.cpp:46:9: error: 'db' was not declared in this scope
         db.Insert(id, std::move(name), x, y);
         ^~
main.cpp:51:34: error: 'db' was not declared in this scope
             for (const auto& e : db.DataByPosition(i, j))
                                  ^~
main.cpp:55:34: error: 'db' was not declared in this scope
             for (const auto& e : db.DataByName(string() + i + j))
                                  ^~
main.cpp:57:26: error: 'db' was not declared in this scope
     for (const auto& e : db.Data())
                          ^~