In this chapter Scott Meyer mentioned a few technique to avoid header files dependency. The main goal is to avoid recompiling a cpp file if changes are limited to other included header files.
My questions are:
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In my past projects I never paid attention to this rule. The compilation time is not short but it is not intolerable. It could have more to do with the scale (or the lack of) of my projects. How practical is this tip today given the advance in the compiler technology (e.g. clang)?
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Where can I find more examples of the use of this techniques? (e.g. Gnome or other OSS projects)
P.S. I am using the 2nd edition.
I don’t think compiler technology has advanced particularly. clang is not some piece of magic – if you have dependencies then and you make changes, then dependent code will have to be recompiled. This can take a very, very long time – read hours, or even days for a big project, so people try to minimise such dependencies where possible.
Having said that, it is possible to overdo things – making all classes into PIMPLs, forward declaring everything, etc. Doing this just leads to obfuscated code, and should be avoided whenever possible.