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tpochep@mail.ru · Guest

Hello.

I have example of ill-formed(???) code.

template<class T>
class Enclose {
public:
template<class T1>
class Nested0 {
template<class T2>
friend class Nested0;
};
class Nested1 : public Nested0<T>{};
};

int main()
{
Enclose<int>::Nested1 a;
}
g++ (and VC 7.1) can compile it.

Comeau online:

"ComeauTest.c", line 7: error: template nesting depth does not match
the previous
declaration of class template "Enclose<T>::Nested0 [with
T=int]"
friend class Nested0;
^
detected during:
instantiation of class
"Enclose<T>::Nested0<T1> [with T=int, T1=int]" at
line 9
instantiation of class "Enclose<T>::Nested1 [with T=int]"
at line
14

Ok, I can fix it:

template<class T>
class Enclose {
public:
template<class T1>
class Nested0 {
template<class T2>template<class T3>
friend class Enclose<T2>::Nested0;
};
class Nested1 : public Nested0<T>{};
};

int main()
{
Enclose<int>::Nested1 a;
}

Now, it's compilable by como.
The question is: does standard define such behavior and where (if it
does) ?

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