You can probably live without stuff like runtime type information and exceptions in a kernel. What remains is trivial stuff like global constructors, stuff like file access which you will be implementing yourself anyways, and stuff that requires dynamic allocation, like std::vector, std::string, but those have template arguments for specifying custom allocators. And if you're not #includeing the specific headers, you don't need to support that shit ¯\_(ツ)_/¯

CC: @p@fsebugoutzone.org @shibao@misskey.bubbletea.dev