#include <sys/resource.h>
#define ck(x) if( (x)==(-1)){ perror(""); exit(EXIT_FAILURE);}

/* this is a rsuage struct */
/*
struct  rusage {
        struct timeval ru_utime;        /o user time used o/
        struct timeval ru_stime;        /o system time used o/
                                        /o actual values kept in proc struct o/
        long    ru_maxrss;
#define ru_first        ru_ixrss
        long    ru_ixrss;               /o integral shared memory size o/
        long    ru_idrss;               /o integral unshared data " o/
        long    ru_isrss;               /o integral unshared stack " o/
        long    ru_minflt;              /o page reclaims o/
        long    ru_majflt;              /o page faults o/
        long    ru_nswap;               /o swaps o/
        long    ru_inblock;             /o block input operations o/
        long    ru_oublock;             /o block output operations o/
        long    ru_ioch;                /o # of characters read/written o/
        long    ru_msgsnd;              /o messages sent o/
        long    ru_msgrcv;              /o messages received o/
        long    ru_nsignals;            /o signals received o/
        long    ru_nvcsw;               /o voluntary context switches o/
        long    ru_nivcsw;              /o involuntary " o/
#define ru_last         ru_nivcsw
};  */

void foo(void)
{
	/* do stuff */
}
int main()
{
    struct rusage start={0,0};
    struct rusage end={0,0};
    struct rusage *pend=&end;
    struct rusage *pstart=&start;

    ck(getrusage(RUSAGE_SELF,pstart)); /* get start point */
    foo();                                                  /* run function(s) */
    ck(getrusage(RUSAGE_SELF,pend));  /* get end point */
    /* print the diff of pend and pstart values for memory items you want here */
    printf("difference: %d\n", pend->ru_ixrss - pstart->ru_ixrss);
    return 0;
}

ck(getrusage(RUSAGE_SELF,pstart)); /* get start point */	
my_func();
ck(getrusage(RUSAGE_SELF,pend));  /* get end point */
std::cout<<pend->ru_ixrss - pstart->ru_ixrss<<" pend: "<<pend->ru_ixrss<<std::endl;