Re: Profiler class, suggestions and comments welcome

From:

Francesco <entuland@gmail.com>

Newsgroups:

comp.lang.c++

Date:

Wed, 19 Aug 2009 12:34:53 -0700 (PDT)

Message-ID:

<e5a097a9-324b-483b-aa87-f89559845b87@r34g2000vba.googlegroups.com>

On 19 Ago, 21:11, Victor Bazarov <v.Abaza...@comAcast.net> wrote:

Francesco wrote:

[..]
std::string profiler::report() {
  timing_map_type::const_iterator iter;
  std::stringstream res;
  for(iter = t_map.begin(); iter != t_map.end(); ++iter) {
    res << iter->first << "\n";
    const timing_record& tr = iter->second;
    res << "Calls: " << tr.hits << ", ";
    res << "avg time: " << tr.used_time / tr.hits << "\n";
  }
  return res.str();
}
-------

A style nitpick. Since 'iter' is not used after the loop, I would
declare it in the 'for' statement itself (so that the scope is not
polluted by the variables that aren't used). And since 't_map' is not
changing during this, a *potential* performance improvement might be to
get the 'end' once, like so:

    std::ostringstream res;
    for (timing_map_type::const_iterator iter = t_map.begin(),
                                    =

e = t_map.end();

         iter != e;
         ++iter) {
      ....
    }

Good idea. I'll perform the change you suggested to my code.

I recall doing something like this somewhere else in my past coding.
But I did it declaring and setting those variables before the loop -
just like I here above. Thank you for recalling me of that
optimization.

About the rest of my code I assume "news.none() == news.good()" ;-)

Cheers,
Francesco