On Tue, 2015-06-30 at 12:06 +0200, Murray Cumming wrote: > > > And would you agree that Ubuntu (for instance) will have to do the > > > same thing when C++11 (--std=c++11) becomes the default in g++ 6, > > > when they use g++ 6? > > > > No. Assuming gcc-6 still provides libstdc++ with both ABIs (my > guess > > is that gcc will do so for a considerable number of releases), then > it > > would depend on whether ubuntu chooses to use the new ABI instead of > > the old one for its C++ binaries. > > Isn't Ubuntu likely to make the same choice that Fedora has made, at > least at some point? > > Or is Fedora just doing this (using the C++11 libstdc++ API) because > they really like C++11 and want to make the C++11 experience as good > as > possible?
It looks like Ubuntu does plan to use gcc 5 in Ubuntu 15.10 (in development now): http://summit.ubuntu.com/uos-1505/meeting/22506/gcc-5-update-for-1510/ though it's currently still using gcc 4.9.2: http://packages.ubuntu.com/search?suite=wily&keywords=gcc The plan isn't clear to me, but they are maybe going to try doing parallel-installs of all the affected libraries, though that seems unmanageable to me: http://pad.ubuntu.com/uos-1505-gcc-5-update-for-1510 These are the meeting notes. If you can't log in to see that, here's a copy/paste of part of the current contents: " == libstdc++ ABI transition === * libstdc++ doesn't change the soname, provides a dual ABI * having objects with both ABIs in a process is doomed to fail. * libraries depending on libstdc++ may need to change their ABI How to see: * build the library with GCC 5 * if the library exports some __cxx11 symbols, it may be incompatible, if these are symbols which form part of the public API * To be conservative, you want to assume that the library is incompatible. * If the library is incompatible, rename the package, append "c++11" to the name of the package. * Instead of renaming, support ABI coexistence like libstdc++ (maybe some upstreams will do that) * To build code with gcc-5 which is compatible with the old ABI, define the macro _GLIBCXX_USE_CXX11_ABI to 0 before including any C++ standard library headers. Should only be used for leaf packages, not for libraries as a last resort. " -- Murray Cumming murr...@murrayc.com www.murrayc.com _______________________________________________ gtkmm-list mailing list gtkmm-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtkmm-list
