Comparison chart of D and C++ templates

[Yauheni Akhotnikau]

On Fri, 19 Jan 2007 13:02:47 +0300, Walter Bright  
<newshound at digitalmars.com> wrote:

> http://www.digitalmars.com/d/template-comparison.html
>
> Comments?

In the sample:

template<class T>
   class Foo
{
   typedef int A;
};
template<class T>
   class Bar : Foo<T>
{
   A x; // error
};

it's more correctly to use protected or public keyword in Foo, I think:

template<class T>
   class Foo
{
protected:
   typedef int A;
};

because in original code A is a private member of Foo and cannot be  
accessed from derived classes.

And a question. It's necessary to use 'typename T<U>::' in C++ to access  
to typedef in some template class. Even when classes are not related as  
base/derived:

template< class T >
struct Iterator
{
	typedef T    value_type;
	typedef T *  pointer_type;
};

template< class I >
struct IteratorAdapter
{
	typename Iterator< I >::pointer_type ptr;
};

int
main()
{
	IteratorAdapter< int > a;
}

I think the same situation is in your sample, because Foo<T> is a template  
class and it is necessary to use 'typename Foo<T>::' as a prefix for A in  
Base. So, do you think your sample 'Dependent Base Class Lookup' is  
correct in this context? May be better to speak about access to  
typedefs/alias in D's templates without 'typename' keyword?

-- 
Regards,
Yauheni Akhotnikau