-## Representing the simulated time
-
-SimGrid uses `double` for representing the simulated time:
-
-* durations are expressed in seconds;
-
-* timepoints are expressed as seconds from the beginning of the simulation.
-
-In contrast, all the C++ APIs use `std::chrono::duration` and
-`std::chrono::time_point`. They are used in:
-
-* `std::this_thread::wait_for()` and `std::this_thread::wait_until()`;
-
-* `future.wait_for()` and `future.wait_until()`;
-
-* `condvar.wait_for()` and `condvar.wait_until()`.
-
-We can define `future.wait_for(duration)` and `future.wait_until(timepoint)`
-for our futures but for better compatibility with standard C++ code, we might
-want to define versions expecting `std::chrono::duration` and
-`std::chrono::time_point`.
-
-For time points, we need to define a clock (which meets the
-[TrivialClock](http://en.cppreference.com/w/cpp/concept/TrivialClock)
-requirements, see
-[`[time.clock.req]`](http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4296.pdf#page=642)
-working in the simulated time in the C++14 standard):
-
-@code{cpp}
-struct SimulationClock {
- using rep = double;
- using period = std::ratio<1>;
- using duration = std::chrono::duration<rep, period>;
- using time_point = std::chrono::time_point<SimulationClock, duration>;
- static constexpr bool is_steady = true;
- static time_point now()
- {
- return time_point(duration(SIMIX_get_clock()));
- }
-};
-@endcode
-
-A time point in the simulation is a time point using this clock:
-
-@code{cpp}
-template<class Duration>
-using SimulationTimePoint =
- std::chrono::time_point<SimulationClock, Duration>;
-@endcode
-
-This is used for example in `simgrid::s4u::this_actor::sleep_for()` and
-`simgrid::s4u::this_actor::sleep_until()`:
-
-@code{cpp}
-void sleep_for(double duration)
-{
- if (duration > 0)
- simcall_process_sleep(duration);
-}
-
-void sleep_until(double timeout)
-{
- double now = SIMIX_get_clock();
- if (timeout > now)
- simcall_process_sleep(timeout - now);
-}
-
-template<class Rep, class Period>
-void sleep_for(std::chrono::duration<Rep, Period> duration)
-{
- auto seconds =
- std::chrono::duration_cast<SimulationClockDuration>(duration);
- this_actor::sleep_for(seconds.count());
-}
-
-template<class Duration>
-void sleep_until(const SimulationTimePoint<Duration>& timeout_time)
-{
- auto timeout_native =
- std::chrono::time_point_cast<SimulationClockDuration>(timeout_time);
- this_actor::sleep_until(timeout_native.time_since_epoch().count());
-}
-@endcode
-
-Which means it is possible to use (since C++14):
-
-@code{cpp}
-using namespace std::chrono_literals;
-simgrid::s4u::actor::sleep_for(42s);
-@endcode
-
