<chrono> c++11

As time library, chrono both the header file name, but also a sub-namespace:
that is, in the header file all the elements (except common type format) is not directly defined in the
std namespace (most of the standard library), but in the std :: namespace namespace.

The first document element processing time, mainly in three main ways:

 

Durataions- duration
They measure time span, for example: 1 minute, 2 hours, or 10 milliseconds.
In this library, they are represented by the duration of the object class template, and a cycle count indicates coupled precision (e.g., 10 msec having a count represents 10,
and a millisecond cycle accuracy).

 

Time points- time point
mention a specific point in time, such as a person's birthday, dawn today, or next train elapsed time.
In this library, the object class template by using time_point duration with respect to the epoch (the same clock time common to all fixed points time_point objects)
to express it.

 

Clocks- clock
time point of contact with the actual physical time framework.
The library provides at least three clock, the current time to provide a method time_point expressed as: system_clock, steady_clock and high_resolution_clock.