std::timespec
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                    |   Defined in header  <ctime>
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|   struct timespec;  | 
(since C++17) | |
Structure holding an interval broken down into seconds and nanoseconds.
Member objects
  std::time_t tv_sec
 | 
whole seconds – >= 0 | 
  long tv_nsec
 | 
nanoseconds – [0, 999999999] | 
See also
|    (C++17)  | 
   returns the calendar time in seconds and nanoseconds based on a given time base   (function)  | 
|    calendar time type  (class)  |