Error compiling code with auto_ptr

[Tron Thomas]

The following code, which is perfectly valid C++, fails to compile using 
the command "g++ -g -Wall -ansi -pedantic -c":

#include <memory>

typedef std::auto_ptr<int> IntPtr;

int main()
{
   IntPtr intPtr(NULL);

   intPtr = IntPtr(new int(0));

   return 0;
}

The error message is:

: In function `int main ()':
9: no match for `IntPtr & = IntPtr'
/usr/include/g++-3/memory:40: candidates are: auto_ptr<_Tp>
&auto_ptr<_Tp>::operator= (auto_ptr<_Tp> &) [with _Tp = int]
/usr/include/g++-3/memory:48:                 auto_ptr<_Tp>
&auto_ptr<_Tp>::operator= (auto_ptr<_Tp1> &) [with _Tp1 = int, _Tp =
int]

This problem was found on RedHat Linux 7.2 (Intel), using version 2.96 
of the GNU compiler.