I want to understand which version of clang Apple installed in my macbook, to see with c++11 and/or c++14 features are available.
I typed this command:
Wikipedia's Xcode page has a map of Apple to LLVM versions. The LLVM column has the open-source LLVM/Clang version. From this you can look up a language feature in cppreference's chart of compiler support for language features.