CSTD sets -std= in CFLAGS, but not CXXFLAGS. It should do it for both (the reason why I didn't commit a change immediately is that it requires discussion and testing via a ports tinderbox).
Since the standard names for C and C++ are different, you cannot really use the CSTD variable. I would suggest using CXXSTD, which is consistent with all the other "CXX" prefixes. The available options should probably be: * c++98 * gnu++98 * c++03 * gnu++03 * c++0x * gnu++0x * c++11 * gnu++11 * c++1y * gnu++1y * c++14 (these are only available from clang 3.5 and higher) * gnu++14 Although the usefulness of the 03, 0x and 1y 'standards' is debatable, at least for the base system. For ports, all of these should obviously be available.
Added by ngie@ in e8067928ff5f8
^Triage: assigning to committer who resolved the issue