On Sun, May 14, 2006 at 05:09:28PM +0200, Silex wrote:
Would boost be interested by including this class in boost::timer ?
Even more so when it had microsecond precision.
I'm all ear for your suggestions / bugs / whatever fits it :)
It would be better when the object itself can be handled as variable (independent of it's internal structure). For that to work best, there shouldn't be any 'double's in the internal structure. Two int's, one for seconds and one for microseconds, would be best, imho. There could be an accessor to get a rounded double in seconds, ie 'rseconds()' (I'd reserve 'seconds()' for returning the integer number of seconds. Now, there is a problem imho with it's type: An absolute time is different from a relative time. The fact that an absolute time is relative to 1 Jan 1970 0:00:00 would make one confused- thinking that the two are the same thing, but I'd argue that it would be better to make TWO types. You could use boost::Time for a real time (in UTC), and boost::TimeDiff to represent time intervals. For example, boost::Time start; // Uninitialized object. assert(!start); // Not initialized. start.set(); // Set to current time. assert(start); // Initialized. // Do work... boost::TimeDiff elapsed = boost::Time() - start; // Time is automatically initialized when used. There would be a Time::set(time_t seconds), Time::set(time_t seconds, suseconds_t microseconds), and Time::set(double seconds); And of course, we'd have: Time + Time // error Time - Time = TimeDiff Time +/- TimeDiff = Time TimeDiff + Time = Time TimeDiff - Time // error TimeDiff +/- TimeDiff = TimeDiff Both classes, or just TimeDiff(?), could have accessors for seconds and microseconds. It should be possible to compare TimeDiff with an integer (seconds), assuming 0 for the microseconds part, ie: TimeDiff elapsed = stop - start; if (elapsed > 2) std::cout << "More than 2 seconds have passed.\n"; I'm inclined to think that operator== should NOT be defined for TimeDiff == int, and certainly not for TimeDiff == double (I'm afraid that TimeDiff == TimeDiff has to exist). But operator> and operator< should. For example, if (elapsed >= 0.1) // 100 ms or more elapsed? ...
I just thought that I could also rename it to lowres_timer instead of precise_timer, it's more accurate, what do you think ?
Low resolution would mean it is less precise. As you might have seen, I'd propose to use Time and TimeDiff. The reason that I think that a 'Time' and 'TimeDiff' approach is more useful than a 'HiResTimer', is that you can implement the latter with the first, but not the other way around. Boost should provide a portable interface for the lowest level. Carlo Wood