This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: Share ebo helper throughout lib


On 25/07/18 21:42 +0200, François Dumont wrote:
Hi

    It has already been noticed that there are 2 ebo helpers in the lib. Here is a patch to use 1.


    * include/bits/ebo_helper.h: New.
    * include/Makefile.am: Add latter.
    * include/Makefile.in: Regenerate.
    * include/bits/hashtable_policy.h: Adapt.
    * include/bits/shared_ptr_base.h: Adapt.

I think we want an extra template parameter which is used for a tag
type, to guarantee that the two uses (in hash tables and in shared
ptr) can never conflict and produce ambiguous bases.

i.e.

 template<int _Nm, typename _Tp, typename _Tag,
        bool __use_ebo = !__is_final(_Tp) && __is_empty(_Tp)>
   struct _Ebo_helper;

and:

using _Sp_ebo_helper = __detail::_Ebo_helper<_Nm, _Tp, _Sp_counted_base<>>;

(for example).



Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]