Discussion on: How To Include ‘bits/stdc++.h’ Header File With Clang Compiler on macOS

[Paul J. Lucas]

1. Anything in the bits directory is for the implementation and it not supposed to be included by your end project.
2. You shouldn't be modifying anything inside the Xcode.app directory. Whenever you upgrade, that directory will be overwritten anyway.
3. Always including everything slows compilation times way down.
4. Assuming you want to write portable code, just #include what you're supposed to include.

This is simply bad advice.