-----Original Message----- From: boost-bounces@lists.boost.org [mailto:boost-bounces@lists.boost.org] On Behalf Of Emil Dotchevski Sent: Sunday, November 08, 2009 7:20 PM To: boost@lists.boost.org Subject: Re: [boost] Official warnings policy?
With his permission: "While /Za is supported (both by the compiler and the standard library), we recommend against using it. Although it increases conformance in several areas (e.g. preventing unqualified name lookup from reaching into dependent base classes), it isn't subjected to exhaustive testing like the default setting is. There have been and will probably continue to be examples of /Za exposing compiler bugs that otherwise aren't exposed. For example, during VC10's development, /Za's elided copy constructor check was being triggered during move construction, when no copy constructor is being called (even theoretically). In particular, if you compile with multiple compilers, /Za isn't very useful - other compilers will detect nonconformant code that /Za would have detected."
I would add that it my experience /Za doesn't make MSVC fully conformant anyway (I mean, in practice, not only in theory) and given
Thanks for this definitive and informed comment. I might have been less 'sniffy' about it if I had seen the full quote ;-) But I still believe that there may be value in Boost trying to use /Za for the simple reason that, despite his " /Za isn't very useful" view, it *may* still be useful for detecting portability problems, at the very least if it is found that MS Extensions *are* needed. I still believe that the work in fixing or suppressing warnings will actually be small, and will be worth it. Even if we don't find a single bug, that fact that we have tried harder gives Boost a Quality feel. Paul --- Paul A. Bristow Prizet Farmhouse Kendal, UK LA8 8AB +44 1539 561830, mobile +44 7714330204 pbristow@hetp.u-net.com