Re: [boost] Loki SmartPtr study: Policy orthogonality issues

From: Peter Dimov (pdimov_at_[hidden])
Date: 2002-01-14 10:10:31

From: "Beman Dawes" <bdawes_at_[hidden]>
> Yes, agreed.  This is the approach Peter Dimov has been advocating.  But I
> can't get it to compile with either GCC 3.0.1 or VC++7.0b2. See code
below.
>
> GCC says:
>
> policy_ptr.cpp: In instantiation of `default_checking<int, policy_ptr<int,
> default_checking, default_storage> >':
> policy_ptr.cpp:37:   instantiated from `policy_ptr<int, default_checking,
> default_storage>'
> policy_ptr.cpp:37:   instantiated from here
> policy_ptr.cpp:34: no type named `storage_policy' in `class
policy_ptr<int,
>
>     default_checking, default_storage>'
>
> line 34 is the line that reads:   void check(
> typename   SmartPtr::storage_policy::pointer_type p ) const
>
> Any ideas?

You can't access SmartPtr::storage_policy in a member declaration since
SmartPtr is incomplete at this point.

You can access it in the member function body, though.

Tying this to my previous question, what is the reason of the 'pointer_type'
(over)generalization? When is pointer_type not T*? std::allocator flashes?

--
Peter Dimov
Multi Media Ltd.