[Rd] Experimental CXX_STD problem in R 3.4

[Jeroen Ooms]

On Sun, Mar 19, 2017 at 9:09 PM, Martyn Plummer <plummerm at iarc.fr> wrote:
> I have just added some code to ensure that the compilation fails with an informative error message if a specific C++ standard is requested but the corresponding compiler has not been defined. Please test this.

Are you sure we shouldn't just fall back on a previous standard
instead of failing? For example if the package author has specified a
preference for CXX14 but the compiler only has CXX11, the package
might still build with -std=c++11 (given that C++14 is only a small
extension on the C++11 standard).

The current behavior (in R 3.3) for packages with "CXX_STD=CXX11" is
to fall back on CXX when the compiler does not have CXX1X. Will R-3.4
start failing these packages? This would affect many users on CentOS 6
(gcc 4.4.7).