Re: [Boost-Users] Re: [boost] Iterator Adaptor Poll

From: Beman Dawes (bdawes_at_[hidden])
Date: 2002-07-26 16:30:13

At 02:48 PM 7/26/2002, David Abrahams wrote:

 >> > Another thing that still confuses me is why you need to specify 
Value,
 >> but
 >> > can let Reference, Pointer, and Distance default.
 >>
 >> It's all spelled out in the table. The default value_type is
 >> iterator_traits<slist_node*>::value_type == slist_node, not slist_data.
 >
 >To further clarify, as the table says, the defaults for Reference, 
Pointer,
 >and Distance are not taken from the Base type, but from the Value type.
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 

 >Once we specify that the Value type is slist_data, we get slist_data& and
 >slist_data* for free.

I was misreading the table as always using the Base type as the default. 
Sigh.

--Beman