g++ 1.1b : template problem with enum

["Isabelle Dauthieu p.36 236" <dauthieu at onera dot fr>]

The problems evocated in this mail are encountered with egcs1.1b both on Linux 
(GNU/Debian on Pentium) and on Solaris2.6 (on Sun4 station)

I encountered some problem with the following code :
----------test.cc--------------------------------
namespace test
{
  template <class T>
  class Temp
  {
  public:
    typedef enum
    {
      empty,
      full
    } State;
  private:
    class Bug
    {
    public:
      Bug(const T& toto, const State& state);
    private:
      T m_toto;
      State m_state;
    };
  public:
    Temp(const T&);
  private:
    Bug<T> m_bug;
  };
}

template <class T> test::Temp<T>::Bug::Bug(const T& toto, const 
test::Temp<T>::State& state)
  : m_toto(toto), m_state(state)
{}

template <class T> test::Temp<T>::Temp(const T& toto)
  : m_bug(toto, test::Temp<T>::empty)
{}

// instanciations
template class test::Temp<int>;
template class test::Temp<int>::Bug;

int main(int, char **)
{
  test::Temp<int> temp(0);
}
--------------------------------------------------
when compiling with the command : 
gcc -Wall -fno-implicit-templates test.cc -o test

the results of the compilation are :
test.cc:29: prototype for `::test::Temp<T>::Bug::Bug(const T &, enum 
::test::Temp<T>::State &)' does not match any in class `::test::Temp<T>::Bug'
test.cc:16: candidate is: ::test::Temp<T>::Bug::Bug(const T &, const enum 
::test::Temp<T>::State &)
test.cc: In method `::test::Temp<T>::Bug::Bug(const T &, enum 
::test::Temp<T>::State &)':
test.cc:29: template definition of non-template `::test::Temp<T>::Bug::Bug(const 
T &, enum ::test::Temp<T>::State &)'
test.cc: In function `int main(int, char **)':
test.cc:42: warning: unused variable `class ::test::::test::Temp<int> temp'
test.cc: In method `::test::::test::Temp<int>::Temp<int>(const int &)':
test.cc:37:   instantiated from here
test.cc:33: warning: initialization of non-const reference `enum 
::test::::test::Temp<int>::State &' from rvalue 
`::test::::test::Temp<int>::State'
test.cc:16: warning: in passing argument 2 of `Temp<int>::Bug::Bug<int>(const 
int &, ::test::::test::Temp<int>::State &)'


It seems the compiler didn't see the const in the definition of the Bug 
constructor. (Or perhaps I misunderstood something).
Is it a compiler bug, or did I miswrite something ?

If I comment the const in the declaration of the Bug constructor, the compiler 
tells me:
test.cc: In function `int main(int, char **)':
test.cc:42: warning: unused variable `class ::test::::test::Temp<int> temp'
test.cc: In method `::test::::test::Temp<int>::Temp<int>(const int &)':
test.cc:37:   instantiated from here
test.cc:33: warning: initialization of non-const reference `enum 
::test::::test::Temp<int>::State &' from rvalue 
`::test::::test::Temp<int>::State'
test.cc:29: warning: in passing argument 2 of `Temp<int>::Bug::Bug<int>(const 
int &, ::test::::test::Temp<int>::State &)'

I don't understand the second warning (l33). Could someone explain me what 
happens here ?

And last question : why do I need to explicitely instanciate 
test::Temp<int>::Bug, shouldn't it be instanciated with the first instanciation 
(test::Temp<int>) ?


Isabelle Dauthieu
dauthieu@onera.fr