I'm confused by the premise: > dropping C++11 requirement allowed me to make sure anybody can compile the library on any platform, removing std::vector substan

I'm confused by the premise: > dropping C++11 requirement allowed me to make sure anybody can compile the library on any platform, removing std::vector substantially improved performance of unoptimized builds What platform doesn't have C++11 support? And why is the performance of an unoptimized build interesting? -O2 is basically a standard compiler flag...?