Re: Selecting a C++ standard

[Paul Eggert]

On 10/28/2012 04:07 AM, Roger Leigh wrote:
> If I want C11, I certainly won't find the C99 or C89
> fallbacks useful at all.  I want it to fail there and then.

I'm afraid that if you want C11, then the only reasonable
implementation right now is something like this:

  AC_MSG_ERROR([C11 is not supported on this platform])

because there are no C11 implementations yet.

Eventually something better may turn up.  But in the
meantime, packages using C11 features (such as Emacs)
are typically doing it in the Autoconf Way, namely,
by testing for the specific feature and using it if available.
This philosophy permeates Autoconf pretty thoroughly.