Home/ Questions/Q 6143293
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-23T18:30:24+00:00

To speed up the compilation of a large source file does it make more

  • 0

To speed up the compilation of a large source file does it make more sense to prune back the sheer number of headers used in a translation unit, or does the cost of compiling code far outweigh the time it takes to process-out an include-guarded header?

If the latter is true an engineering effort would be better spent creating more, lightweight headers instead of less.

So how long does it take for a modern compiler to handle a header that is effectively include-guarded out? At what point would the inclusion of such headers become a hit on compilation performance?

(related to this question)

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    The answer:

    It can be very expensive!

    I found an article where someone had done some testing of the very issue addressed here, and am astonished to find you can increase your compilation time under MSVC by at least an order of magnitude if you write your include guards properly:

    http://www.bobarcher.org/software/include/index.html

    The most astonishing line from the results is that a test file compiled under MSVC 2008 goes from 5.48s to 0.13s given the right include guard methodology.

    • 0