#include"stdio.h"
void foo_v1(int f) {
     printf("foo_v1\n");
}
__asm__(".symver foo_v1,foo@@VERSION_1.1");

class Clock
{
    public:void SetTime(int NewH, int NewM, int NewS);
};

void  Clock::SetTime(int H, int M, int S)
{
      int  Hour = H;
      int  Minute = M;
      int  Second = S;
      printf("%d %d %d", Hour, Minute, Second);
}
__asm__(".symver SetTime ,SetTime@@VERSION_1.1");

//这是上边说的1.ver
VERSION_1.1{
      global:
      foo;
      Clock::*;

};

gcc -shared -fPIC -o libfoo.so.1.1 -Wl,--soname='libfoo.so.1' -Wl,--version-script=1.ver foo.c

#include <stdio.h>
class Clock;
void foo(int);
int main()
{
    Clock myClock;
    foo(100);
    myclock.SetTime(10, 12, 14);
    return 0;
}

main.cpp: In function `int main()':
main.cpp:6: error: aggregate `Clock myClock' has incomplete type and cannot be defined