What is my version of LLVM & clang (OSX)?

Question

On Mac OS, if I run clang --version, I get:

Apple LLVM version 6.0 (clang-600.0.34.4) (based on LLVM 3.5svn)
Target: x86_64-apple-darwin14.0.0
Thread model: posix

Since LLVM official page suggests that the current LLVM version is 3.5, it seems that Apple clang versioning is distinct from the open-source LLVM. The output (based on LLVM 3.5svn) suggests that probably it is 3.5 on my machine as well.

Now I got here since I wanted to compile a C++14 file, using g++ -std=c++14 main.cc. This page suggests that this option should work on clang 3.5. However, it works only with -std=c++1y, which works on clang 3.4 or earlier.

So what is LLVM open-source version equivalent for Apple's version? It seems 3.5 but then why it doesn't work so?

Answer 1

It is some Version of the llvm 3.5 svn branch before the official 3.5 release version.

Meaning that it probably should have all features of 3.4 plus some of the 3.5 features.