c++ - undefined reference to `vtable for class

I have take code from cppfaq 12.15 and trying to compile
but getting error in linux with gcc version 4.8.4.

undefined
reference to `vtable
for

I am surprise
as I do not have any virtual method. I have looked into following question but not able
figure out issue.

href="https://stackoverflow.com/questions/4272432/c-undefined-reference-to-vtable">c++
undefined reference to
vtable

href="https://stackoverflow.com/questions/7665190/undefined-reference-to-vtable-for-xxx">Undefined
reference to 'vtable for xxx'

The
code

#include
#include
#include
            using namespace std;

class Fred; typedef auto_ptr
            FredPtr;


class Fred {
 public:

            static FredPtr create() throw(bad_alloc);
 static FredPtr create(int i)
            throw(bad_alloc);
 static FredPtr create(const Fred& x)
            throw(bad_alloc);
 virtual void goBowling();
 private:

            Fred(int i=10);
 Fred(const Fred& x);
 int
            i_;

 };

FredPtr Fred::create() throw
            (bad_alloc) { return auto_ptr(new Fred()); }

FredPtr
            Fred::create(int i) throw(bad_alloc) {
 return auto_ptr(new
            Fred(i)); }

FredPtr Fred::create(const Fred& x)
            throw(bad_alloc) {
 return auto_ptr(new Fred(x));
            }


Fred::Fred(int i) {
 i_ = i;

            cout<<" This is simple constructor"<            }

Fred::Fred(const Fred& x) {
 i_ = x.i_;

            cout<<" This is copy constrcutor"<
void
            sample() {
 FredPtr p(Fred::create(5));


            p->goBowling(); }

int main() {
 sample();

            return 0;
            }

Error:

/tmp/cc6JnLMO.o:
            In function `Fred::Fred(int)':

cpp12_15.cpp:(.text+0x204):
            undefined reference to `vtable for Fred'
/tmp/cc6JnLMO.o: In function
            `Fred::Fred(Fred const&)':
cpp12_15.cpp:(.text+0x247): undefined reference
            to `vtable for Fred'
collect2: error: ld returned 1 exit status