clock_t

From cppreference.com
< c‎ | chrono
Defined in header <time.h>
typedef /* unspecified */ clock_t;

Arithmetic type capable of representing the process running time of implementation-defined range and precision.

[edit] See also

returns raw processor clock time since the program is started
(function)
number of processor clock ticks per second
(macro constant)
C++ documentation for clock_t