forward_list patch for ext pointer support

[Bob Walters <bob dot s dot walters at gmail dot com>]

Paolo,

I'm posting the changes to forward_list which adds support for  
extended pointers, as requested.   This patch is dependent on the  
nonstd_pointer patch.   I have tested that this applies fine on top of  
the nonstd_pointer.patch using patch -p0 <forward_list.patch.

All of the changes to forward_list were superficial.  The Allocator  
had to be added to the Fwd_list_node_base and Fwd_list_node  
definitions, and to the iterators, allowing them to use the pointer  
typedef in turn.  Beyond that what you will see throughout the code is  
the use of the pointer typedef rather than the raw pointer types, and  
the use of the __static_pointer_cast in place of the normal static_cast.

Attachment: forward_list.patch
Description: Binary data

ChangeLog:
2008-11-02  Bob Walters <bob.s.walters@gmail.com>

        * include/bits/forward_list.h: Support non-standard pointers
        * include/bits/forward_list.tcc: Support non-standard pointers
        * testsuite/23_containers/forward_list/ext_pointer/*: Add new  
tests        for forward_list<> using non-standard pointers via  
extptr_allocator.
        * include/ext/cast.h: Addd generic versions of pointer cast  
functions
        for pointer class types supporting a simple concept.
        * include/ext/pointer.h: Removed pointer cast operators.
        * include/ext/extptr_allocator.h: Added C++0X construct()  
method.

Tested on Darwin-i686.

Bob