Specifying the C/C++ version with Xcode
1. Open your project inside Xcode.
2. At the left of the window, in the file/folder list, click on the project item.
3. Click on Build Settings.
4. Scroll to Apple Clang - Language.
5. We can choose the C version used.
6. We can also choose the C++ version used.
Note that the difference between the versions starting with C++ and those with GNU is that the GNU versions include additional non-standard features.
7. The Standard Libraries may be implemented (Coded) in many different ways. Its is possible to choose the implementation of the C++ Standard Library: