[Solved] error: ‘getrusage’ was not declared in this scope

Error:

vb_perf.cpp: In function ‘int main(int, const char**)’:

vb_perf.cpp:63:23: error: variable ‘main(int, const char**)::rusage rusage’ has initializer but incomplete type

   63 |         struct rusage rusage = { };

      |                       ^~~~~~

vb_perf.cpp:64:19: error: ‘RUSAGE_SELF’ was not declared in this scope

   64 |         getrusage(RUSAGE_SELF, &rusage);

      |                   ^~~~~~~~~~~

vb_perf.cpp:64:9: error: ‘getrusage’ was not declared in this scope; did you mean ‘rusage’?

   64 |         getrusage(RUSAGE_SELF, &rusage);

      |         ^~~~~~~~~

      |         rusage

Solution:

Include this header to your source code:

#include <sys/resource.h>

This compile error means the program used getrusage and struct rusage without including the header that declares them, so the compiler sees an incomplete type and stops.

Including sys/resource.h, and sys/time.h where needed, brings in the declarations and resolves it. getrusage reports resource usage such as CPU time and memory for the calling process on Unix like systems.