https://www.factorio.com/blog/post/fff-206 "Step 3 - Getting rid of boost Boost is a special kind of demon. It lures you in by giving you all these cool and simple to use features, and then it beats your soul from you by increasing compilation times absurdly. There are two main problems. Problem one is that they don't care much about compile times and two, they want to have everything nice and generic ad absurdum, and they even defend it as the correct style. The result is, that changing boost::mpl::vector66 to std::variant can improve the compile time from 1:44 to 1:20 and getting rid of templates completely by using unions can decrease the compile time to 0:53. I'm talking about changing 2 headers of 2 classes in a project with 3390 files, 410k lines of code and 15Mb of source code. Everything that was compiled to Factorio, GUI, graphics library, networking, entity logic, scripting, modding, logistic system... all these things together took the same time to compile as two instances of boost::mpl::vector. Our current goal is to get rid of the boost library completely."