Auto_ptr<> woes.

Hi,
I have the following test case which is boiled down from real code. The
problem is that Foo * foo (); auto_ptr<Foo> ap; ap = foo (); does not do
what
I thought it should have done. With GCC it does not compile; with MSVC8 it
does compile but breaks. I have stepped through the MSVC8 compiled code
and
it goes through auto_ptr_ref(void *_Right) to auto_ptr<_Ty>&
operator=(auto_ptr_ref<_Ty> _Right).

My questions are: Is MSVC8 right? Should it even compile? Is there
something
in the standard that makes the ap = foo () assignment having undefined
behaviour?


----------------------8<-----------------------
#include <memory>
#include <iostream>

struct Data
{ };


Data *
foo ()
{
     return new Data;
}


int
main ()
{
     {
         std::auto_ptr<Data> ap;
         // This compiles but breaks with MSCV8.
         // and does not compile with GCC.
         ap = foo ();
         std::cout << "ap: " << ap.get () << std::endl;
     }

     {
         // This works as intended.
         std::auto_ptr<Data> ap (foo ());
         std::cout << "ap: " << ap.get () << std::endl;
     }

     std::cin.get ();
}

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