how to declare friend for template class ?

[slocum]

how to declare friend for template class ?

class A
{
public:
.....
private:
.....

friend class B ????????
}

template <class T>
class B
{
}

 

[Martin York]

how to declare friend for template class ?

class A
{
public:
.....
private:
.....

friend class B ????????

}

template <class T>
class B
{

}

You can't.
Though you can defined friends for particular versions of B.

template<typename T>
class B
{
};

class A
{
friend class B<int>;
friend class B<float>;
friend class B<MyType>;
// etc..
};

 

[slocum]

And what about this way ??

template <typename T>
class B
{

};

template <typename T>
class A
{
friend class B<T>;

};

 

[Brian Tyler]

You can't.

Though you can defined friends for particular versions of B.

template<typename T>
class B
{
};

class A
{
friend class B<int>;
friend class B<float>;
friend class B<MyType>;
// etc..
};

That is completely untrue


template<class T> class B
{
// Stuff
};

class A
{
template <class> friend class B;
};

makes B a friend irrespective of the type of it's template parameter.

Brian.

 

[Martin York]

That is completely untrue

class A
{
template <class> friend class B;

};

makes B a friend irrespective of the type of it's template parameter.

Live and learn.