3.3 ABI vs 3.4 ABI (!) vs 3.5 ABI (?)...

[Paolo Carlini]

Hi everyone,

this is only a first heads-up: the issue seems thorny and we should
discuss it in detail next week or, anyway, as soon as possible.

Indeed, seems time to take some "official" decisions, which will profoundly
affect the development in mainline and release branches.

Schematically, at least two points:
 
  1- Are there any hopes to provide some sort of smooth transition between
     3.3 and 3.4? To wit, Michael noticed a few days ago that not that many
     symbols present in 3.3-V3 are not anymore in 3.4. Perhaps, if we really
     want, we can envisage providing "GLIBCXX_ABI Deprecated" code, as we
     did between 3.2 and 3.3, or otherwise, fall back to other strategies.
     On one hand, this is, in my opinion, a "dirty work" ;), which 
perhaps we
     would not really enjoy doing, on the other hand, however, *so* many
     distributions relied and will rely for some time still on 3.3 and
     therefore would be of *major* benefit to the users.

  2- 3.4 vs 3.5: what shall we do? This issue is not less urgent, since 
shapes
     the kind of development that will happen in mainline and/or the need of
     backporting to 3.4 any ABI-breaking change that in the next few 
weeks of
     mainline developmente turns out to be really unavoidable. 
Personally, I'm
     particularly worried by locale and string, which have already diverged
     quite a bit (hopefully still not too much from the ABI point of view),
     but other areas are affected as well.

During the weekend I will think more about those two items... will you?? ;)

Paolo.