Why not include all the standard headers always?

Question

I am reading Herb Sutter\'s More Exceptional C++ and item 37 on forward declarations says:

Never #include a

Answer 1

There is in principle nothing against it.

The only thing that will happen is that your compile times will increase, unless of course you create a precompiled header of that standard_library.h, in which case the impact will be minimal.

Note that most people prefer to minimize their header dependencies. This mostly applies to your own header files, in which case a small change in an unused, but included header in a source file may trigger an unnecessary recompile of said source file for no reason whatsoever, slowing down incremental builds a lot.