fixed_allocator.h:10:  public: should be indented +1 space inside class FixedAllocator  [whitespace/indent] [3]
fixed_allocator.h:16:  Using C-style cast.  Use reinterpret_cast<Tp*>(...) instead  [readability/casting] [4]
fixed_allocator.h:8:  Add #include <vector> for vector<>  [build/include_what_you_use] [4]
fixed_allocator.h:34:  Could not find a newline character at the end of the file.  [whitespace/ending_newline] [5]
Done processing fixed_allocator.h
Total errors found: 4