[xcvb]

I only had a quick look at the code, but it looks like it's timing memory allocation. For example the sprintf part uses std::string str(100, '\0'). I'm not a C++ expert, but I believe this is essentially doing a malloc and memset of 100 bytes for every call to sprintf. So this is probably a poorly setup benchmark.

[lysium]

I think that might be it. Too bad, the results of this kind of benchmark would have been interesting.