Indeed, that particular implementation is very fast. One of the goals of the C++ language is to leave no space for a lower level language than C++. A motivated person could just re-implement those algorithms in C++, in the absolute worst case using inline Assembly and at the very worst exactly match their performance. One of the nice things about Julia is you get good performance without going through a huge amount of effort. However you could always do as good or better in C++(with maybe more effort).