On Nov 18, 2008, at 9:14 AM, Beman Dawes wrote:
The Chrono library in the sandbox is now more-or-less feature complete. In addition to the C++0x features, timers have been added to replace the old Boost.Timer library which will become deprecated.
The feature list includes:
* The C++0x Standard Library's time utilities, including: o Class template duration o Class template time_point o Clocks: + |system_clock| + |monotonic_clock| + |high_resolution_clock| * Class template |timer|, with typedefs: o |system_timer| o |monotonic_timer| o |high_resolution_timer| * Process clocks and timers: o |process_clock|, capturing real, user-CPU, and system-CPU times. o |process_timer|, capturing elapsed real, user-CPU, and system-CPU times. o |run_timer|, convenient reporting of |process_timer| results. * The C++0x Standard Library's compile-time rational arithmetic.
See http://svn.boost.org/svn/boost/sandbox/chrono
The implementation is now working and lightly tested on Windows with VC++ 9.0 SP1 and Intel ia32 11.0 compilers, and on Ubuntu Linux with GCC 4.2.4 compiler.
There is a bit more documentation, but it is still needs much work.
Comments are welcome.
It seems a shame that process_clock does not really meet the proposed standard clock requirements (its now() doesn't return the time_point). That being said, I can see why you didn't. This clock really has 3 distinct "time points" and one needs to set each of those three with one system call. If one wanted, one could easily create a user_time_clock wrapper around processor_clock to adapt it to the standard clock requirements if needed. Just for general education purposes, here's a portable processor-time clock (just to show how easy it is to build a custom clock): #include <ctime> #include <cstdio> #include <chrono> class processor_clock { public: typedef std::clock_t rep; typedef std::ratio<1, CLOCKS_PER_SEC> period; typedef std::chrono::duration<rep, period> duration; typedef std::chrono::time_point<processor_clock> time_point; static const bool is_monotonic = true; static time_point now() {return time_point(duration(std::clock()));} }; int main() { processor_clock::time_point t1 = processor_clock::now(); processor_clock::time_point t2 = processor_clock::now(); std::printf("%g seconds\n", std::chrono::duration<double>(t2- t1).count()); } Output: 4e-06 seconds -Howard