In file included from main.cpp:28:0:
fixed_allocator.h: In instantiation of 'Tp* FixedAllocator<Tp>::Allocate() [with Tp = int]':
main.cpp:45:30:   required from here
fixed_allocator.h:17:25: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
       for (int i = 0; i < _page_size; ++i) {
                       ~~^~~~~~~~~~~~
fixed_allocator.h: In instantiation of 'Tp* FixedAllocator<Tp>::Allocate() [with Tp = std::__cxx11::basic_string<char>]':
main.cpp:57:24:   required from here
fixed_allocator.h:17:25: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
fixed_allocator.h: In instantiation of 'Tp* FixedAllocator<Tp>::Allocate() [with Tp = char]':
main.cpp:119:40:   required from here
fixed_allocator.h:17:25: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
cc1plus: all warnings being treated as errors