On Sat, Oct 27, 2012 at 01:55:58PM -0700, Paul Eggert wrote: > On 10/27/2012 01:38 PM, Roger Leigh wrote: > > Is anyone working on such a thing? > > Not that I know of. > > For C, we're deprecating the "I want version X" > macros in favor of just AC_PROG_CC_STDC, which says > "I want the latest version". You might want to do > that for C++ to, as it's more the Autoconf Way. Sorry to revisit this again, but I got distracted by other things and didn't have time to finish following up at the time. Reading back through the thread, I didn't really feel that we came to any real solution here which would actually allow an autoconf user to usefully enable and use C++11 features. Unless I missed it, I didn't really see any definite conclusions about what to do next. It seems there are two related but somewhat orthogonal requirements here: 1) Putting the compiler into a specific "mode" for a certain level of standards conformance. 2) Feature tests to ensure that certain features are present (or possible to emulate for absent features which can be substituted for). These could be done whether (1) succeeded or failed, but would have a higher chance of success if it succeeded. In order to make use of a C++11 feature, we need to make sure that a best effort has been made to put the compiler into the appropriate mode, e.g. -std=gnu++11. Only once that is done is it meaningful to perform a feature test. Given in the discussion that examples were provided where selecting the latest version was not always a desirable behaviour, is providing the macros for specific standards versions still needed? And with respect to feature test macros, do we need to provide macros for every single language feature, or could we have a core set performed as part of the mode selection which could correspond to the base functionality in GCC (and other compiler) versions implementing that level. This would provide a minimum guarantee of what functionality could be expected (to save every user from having to explicitly check for every common feature needlessly). Regards, Roger -- .''`. Roger Leigh : :' : Debian GNU/Linux http://people.debian.org/~rleigh/ `. `' schroot and sbuild http://alioth.debian.org/projects/buildd-tools `- GPG Public Key F33D 281D 470A B443 6756 147C 07B3 C8BC 4083 E800 _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx https://lists.gnu.org/mailman/listinfo/autoconf
