[PATCH] CMake/Autoconf : perform a sanity check on the compiler support for C++11

[Joerg Sonnenberger]

On Wed, Nov 27, 2013 at 11:45:43AM +0100, Arnaud Allard de Grandmaison wrote:
> The attached patch adds some sanity check on the compiler revision to both
> cmake and configure, so that we fail early (i.e. configure time) and
> clearly when the compiler's revision is known not to fit our requirements
> for C++11 support. The revisions have been extracted from the thread
> initiated by Chandler on cfe-dev/llvm-dev:
>  - g++ >= 4.7.1
>  - clang++ >= 3.1
>  - VS >= 2012

Last time I tried, at least on Cygwin -std=c++11 is almost unusable, so
it might make sense on some platforms to use -std=gnu++11 instead.

Joerg