----- Mensaje original ----- De: Tobias Schwinger <tschwinger@neoscientists.org> Fecha: Domingo, Octubre 17, 2004 1:01 pm Asunto: [boost] Re: [tuple] attempt to fix a BCB regression,and a plea for help
JOAQUIN LOPEZ MU?Z wrote:
Umm... This got me thinking, maybe the whole BCB-specific patch is just overkill, and it only takes to avoid the add_const<> construct. The attached file does just this, i.e. it relies on the default implementation for element<>, using plain const-qualifying instead of add_const<> for BCB. Would you be so kind to give it a try? Thanks in advance.
This new version compiles fine with BCC 5.6.4 but does not compile with BCC 5.5.1 (and versions below this, according to Boost.Config).
The patch is the difference from the file attached to the post I reply to (and not the first file you sent) and makes it work again.
It uses the previous workaround in case BOOST_NO_CV_SPECIALIZATIONS is set. Another check for BCB within this block could be made in order to use 'add_const' for compilers where it works fine (I omitted it, for now).
Here's my (still fuzzy) problem analysis:
1. The "BCC <= 5.5.1 - problem" is that for these versions of BCC cv-specializations don't work.
2. The "add_const - problem" could have something todo with the fact that for BCC 'type const' and 'const type' can be different types. [ see the note regarding the '__BORLANDC__' - block in 'is_const.hpp' ]
As I understand it, the comment you refer to has to do with cv-qualifying references --not our problem now, I think.
I am not sure if and how this affects template argument substitution, but I changed
typename T::head_type const
to
const typename T::head_type
, just in case...
My only objection to your patch is that the problem with add_const is attributed to BOOST_BCB_PARTIAL_SPECIALIZATION_BUG Do you have any reason to think so? I'd prefer to have that part guarded by a simple __BORLANDC__ workaround, given our current (lack of) knowledge about what's causing the problem. If no one complains, I'll commit this stuff to the CVS tomorrow. Thanks everyboydy for your help. Joaquín M López Muñoz Telefónica, Investigación y Desarrollo _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost