#include <vector>
#include <string>
using namespace std;

template< typename _Ptr >
class test{
public:
    typedef vector< _Ptr* > vPtr;
    typedef vPtr::iterator vIPtr;
};
test<int> t;

int main( int ac, char* av[] ){
    return 0;
}

пишет
**** Build of configuration Debug for project map_temp ****

make all
Building file: ../map_temp.cpp
Invoking: GCC C++ Compiler
g++ -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"map_temp.d" -MT"map_temp.d" -o"map_temp.o" "../map_temp.cpp"
../map_temp.cpp:9: error: type ‘std::vector<_Ptr*, std::allocator<_Ptr*> >’ is not derived from type ‘test<_Ptr>’
../map_temp.cpp:9: error: expected ‘;’ before ‘vIPtr’
make: *** [map_temp.o] Ошибка 1

в чём проблема непойму