__restrict cannot be used on references though, for whatever reason. And even though I read an explanation on those forums that references are already thought of to not be able to be rebound, testing it with assembler showed significant worse generated code than with pointers and __restrict (or whatever equivalent).
__restrict can be used on references as of Visual C++ 2015. It was one of the things that I was glad that they added. You also can functionally specify member functions as restrict in 2015 (where this is restrict).