On 10/04/2013 07:39 AM, Tim Tautges wrote: > > On 10/03/2013 05:41 PM, Jed Brown wrote: >> >> Looks like the mailing list had just switched away from google groups >> and wasn't yet being archived, but here's Jack's original message: >> > > That's useful to see, and clearly Jack you didn't make the decision > lightly (au contraire, looks like even preserving compatibility would > have involved more effort than normal; decisions like that are always > difficult...) >
I'm a little late in responding, but, no, the decision was not made lightly. I respect Matt and Karl's (as well as several other colleagues') objections, but I ultimately decided that pushing the library forward by experimenting with simplified programming models was more important than supporting half-decade old compilers. It seems a bit odd to me for someone to simultaenously insist upon a bleeding-edge release of a parallel linear algebra library and a grossly outdated compiler, and I decided not to subvert the growth of a library just for this usecase. I hate to cause unnecessary complications for PETSc, but surely C++11 support has to happen at some point. My apologies for forcing this sooner rather than later. The recently committed distributed blocked Bunch-Kaufman implementation is much simpler because of the combination of 'auto' and move semantics. As far as I am aware, PETSc did not previously support the accurate parallel factorization of symmetric/Hermitian indefinite matrices, and so this is a significant contribution to the library. Jack
