Is it possible to use __restrict__ in C++ on a member variable, like in the example below? (Does it have an effect on functions that take arrays as arguments?) class array { double * __restrict__ data; ... ... }; The documentation only mentions using __restrict__ with function arguments or member functions, and, if I understand correctly, it says that __restrict__ will only have an effect on the function it was used with. http://gcc.gnu.org/onlinedocs/gcc-4.1.2/gcc/Restricted-Pointers.html#index-restricted-pointers-2455