A module for all my uses of the standard library, until import std; works. Due to clang bugs, any file that includes any standard header (even indirectly) must first #include <std_module/prelude.hpp> first. Certain standard headers need to be included in a certain order to ensure the current modules implementation believes function bodies haven't changed, and this ensures that. Moreover, some operators have been defined in such a way that certain things still require #include -- for instance, comparing std::string_view.