I am writing some C++ compiling with g++, and I use the __restrict__ keyword on pointer arrays in some performance critical places to hopefully getting better performance. However, std::vector's [] operator has the neat ability to provide range checking in debug build if the flag _GLIBCXX_DEBUG is specified with g++. However I guess the options to get the __restrict__ benefit is lost if using std::vector as a raw pointer must be used with it.