Константы в С++

#include <iostream>
#include "c++test9.h"

void f(const int *p)
{
        std::cout << "f1" << p << std::endl;
} 

#include <iostream>
#include "c++test9.h"
void h(const int *p)
{
        std::cout << "f2" << p <<std::endl;
} 

const int* x = 0;

#include "c++test9.h"
void f(const int*);
void h(const int*);

int main()
{
        f(x);
        h(x);
}

$g++ -std=c++98 -pedantic -Wall -Wextra c++test9_f1.cc -o c++test9_f1.o -c
%g++ -std=c++98 -pedantic -Wall -Wextra c++test9_f2.cc -o c++test9_f2.o -c
%g++ -std=c++98 -pedantic -Wall -Wextra c++test9.cc -o c++test9.o -c

$g++ c++test9.o c++test9_f1.o c++test9_f2.o
c++test9_f1.o(.bss+0x0): multiple definition of `x'
c++test9.o(.bss+0x0): first defined here
c++test9_f2.o(.bss+0x0): multiple definition of `x'
c++test9.o(.bss+0x0): first defined here