[cfe-dev] Testing for libc++ version number

[Edward Diener]

On the libc++ C++1Y Status web page, at 
http://libcxx.llvm.org/cxx1y_status.html, it mentions at what first 
released version a particular C++1Y feature has been implemented for 
libc++. Is this the _LIBCPP_VERSION macro ? If so what is the format of 
this macro, so I can test its value ? If it is not the _LIBCPP_VERSION 
macro what value is it and how can I test for it at compile time ?