How to avoid namespace content indentation in vim?

Not sure when it was introduced but my installed version of vim, v7.3.353 has a cino option that handles cpp namespace explicitly. I am currently using the example value:

cino=N-s

and as per :help cinoptions-values

NN    Indent inside C++ namespace N characters extra compared to a
  normal block.  (default 0).

cino=                      cino=N-s 
  namespace {                namespace {
      void function();       void function();
  }                          }

  namespace my               namespace my
  {                          {
      void function();       void function();
  }                          }

The link the OP posted is for v7.3.162