在没有 -fPIC 的情况下将静态库链接到共享库

I want to combine object files and a static library into a shared library but the static library shall not be exposed, it is only referred in the object files that go into the shared library. I think that in this case, I do not need to compile the static library with -fPIC but I do not know how to tell the linker that the fact that I will not use the symbols from the static library. As an illustration of my problem, take the following files:

文件foo.cpp:

#include "static.h"
using namespace std;

string version_info()
{
    return static_version_info();
}

文件static.cpp:

#include"static.h"
#include <vector>
using namespace std;
string static_version_info()
{
    std::vector<int> ivec;
    return to_string(ivec.size());
}

文件static.h:

#ifndef STATIC_H
#define STATIC_H
#include<iostream>
using namespace std;
std::string static_version_info();
#endif 

那就做吧

$ g++ -c foo.cpp -o foo.o -fPIC
$ g++ -c static.cpp -o static.o
$ gcc-ar rcs static.a static.o
$ g++ -shared foo.o static.a
/usr/bin/ld: static.a(static.o): relocation R_X86_64_PC32 against symbol `_ZNSt6vectorIiSaIiEEC1Ev' can not be used when making a shared object; recompile with -fPIC
/usr/bin/ld: final link failed: Bad value
collect2: error: ld returned 1 exit status

问题:如何调整最后一个命令，以免出现错误?这可能吗?