[boost] [Root Pointer] Benchmark w/ Threading = 124% faster

I just noticed that if I do not define the BOOST_DISABLE_THREADS macro, root_ptr is faster than allocate_shared_noinit by 124%: unique_ptr (new): 42.1397 unique_ptr (make_unique): 43.4631 shared_ptr (new): 76.4543 shared_ptr (make_shared): 76.6611 shared_ptr (allocate_shared_noinit): 81.9926 root_ptr (new): 66.3417 Thanks, -Phil