On 05/03/2006 01:54 PM, dan marsden wrote:
In boost/fusion/tuple/tuple.hpp there's this: [snip] I don't see any use of the at_meta typedef. What's the purpose of this typedef?
This appears to be the result of a bit of cut and paste from the at and at_c implementations, which also have the redundant typedef. The get implementations should be calling at_c directly, rather than implementing more tag_dispatching to the at_impl type themselves. I've tidied things up, removing the redundant typedefs in both get and at, and modifying get to call at_c directly.
Could you post the location of the revised code?
Thanks for pointing this one out.
Sure. There may be a similar cut and paste problem in /sequence/intrinsic/begin.hpp which has: template <typename Sequence> inline typename result_of::begin<Sequence>::type begin(Sequence& seq) { typedef result_of::begin<Sequence> begin_meta; return extension::begin_impl <typename traits::tag_of<Sequence>::type>:: template apply<Sequence>::call(seq); } Also, the docs in notes.html under "Tag Dispatching" at the 2nd item 3 has: 3. result_of::begin is the template which is specialized to provide an implementation for each tag type yet, in the above begin.hpp, it's not specialized, and a grep of all the .hpp file turned up no likely candidates; however, a grep for 'struct begin_impl' did show several specializations. Is the aforementioned correct?