Tests of support fo C++ Standards
=================================

R itself does not use C++, put provides suppoert for packages to do so
via etc/Makeconf, used by R CMD INSTALL.  The 'configure' script finds
suitable settings for the CXX* macros, but it is not used on Windows.
The test packages in this directory are to allow the settings to be
tested, especially on Windows.

For each standard to be tested, do something like

mkdir Libs
R CMD build testCXX17
R CMD INSTALL testCXX17_1.0.0.tar.gz -l Libs
rm -r Libs testCXX17_1.0.0.tar.gz

C++11 and C++14 are only supported in R < 4.6.0 so their test packages
should fail to install on R >= 4.6.0.  The other standards are
supported in recent versions of R (C++26 for R >= 4.5.3 on Windowss).