std::difftime
From cppreference.com
Defined in header <ctime>
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double difftime( std::time_t time_end, std::time_t time_beg ); |
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Computes difference between two calendar times as std::time_t objects (time_end - time_beg) in seconds. If time_end refers to time point before time_beg then the result is negative.
Parameters
time_beg, time_end | - | times to compare |
Return value
Difference between two times in seconds.
Notes
On POSIX systems, std::time_t is measured in seconds, and difftime
is equivalent to arithmetic subtraction, but C and C++ allow fractional units for time_t
.
Example
Run this code
#include <ctime> #include <iostream> int main() { std::time_t start = std::time(nullptr); volatile double d = 1.0; // some time-consuming operation for (int p = 0; p < 10000; ++p) for (int q = 0; q < 100000; ++q) d = d + p * d * q + d; std::cout << "Wall time passed: " << std::difftime(std::time(nullptr), start) << " s.\n"; }
Possible output:
Wall time passed: 9 s.
See also
(C++11) |
a time interval (class template) |
C documentation for difftime
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